2024年09月, 2024年度日本磁気学会 論文賞, Microwave Transmission Theory for On-Chip Ultrastrong-Coupled Magnon-Polariton in Dynamical Inductors, 日本磁気学会
千葉貴裕;小峰啓史;青野友祐

2024年06月, 第17回日本熱電学会優秀論文賞, 日本熱電学会
村田 正行;鈴木 真理;青山 佳代;長瀬 和夫;大島 博典;山本 淳;長谷川 靖洋;小峰 啓史

2016年09月, Poster Award, The 77th JSAP Autumn Meeting, 2016, Fabrication of Ni₇₈Fe₂₂/Alq₃/Ni₇₈Fe₂₂ nanoscale junctions utilizing thin-film edges and their structural and electrical properties
T. Misawa;S. Mori;T. Komine;N. Hoshino;T. Akutagawa;M. Fujioka;H. Kaiju;J. Nishii
国内学会・会議・シンポジウム等の賞

2015年07月01日, The ITS outstanding research paper award
M. Murata;A. Yamamoto;Y. Hasegawa;T. Komine
国際学会・会議・シンポジウム等の賞

2012年10月, 学術奨励賞(内山賞), ECC媒体における磁気クラスタサイズの磁場印加方向依存性, 日本磁気学会
山口義明;川田裕介;小峰啓史;杉田龍二
国内学会・会議・シンポジウム等の賞

2010年11月, 第58回電気科学技術奨励賞, 磁気転写法によるハードディスクへのサーボ信号超高速記録技術の開発, 電気科学技術奨励会
杉田龍二,小峰啓史
出版社・新聞社・財団等の賞

2009年11月, 優秀講演賞, UV-NIL を用いたナノパターンの作製検討, 電気学会東京支部茨城支所発表会
松本剛,池谷政洋,市毛雄基,高橋光太,東川玲子,櫻井淳光, 小峰啓史,杉田龍二
国内学会・会議・シンポジウム等の賞

2009年09月, 茨城大学学長表彰(奨励賞), 非一様電流による磁壁駆動のマイクロマグネティックシミュレーション, 茨城大学
その他の賞

2008年09月, 学術奨励賞(内山賞), Feasibility of Perpendicular Magnetic Duplication at 1 Tbit/inch2, 日本磁気学会
T. Murata;Y. Sakaguchi;A. Izumi;T. Komine and R. Sugita

2008年09月, 学術奨励賞(内山賞), Micromagnetic Simulation of Current-Induced Domain Wall Motion under a Non-uniform Current Distribution, 日本磁気学会
T. Komine;H. Murakami;T. Nagayama and R. Sugita

2007年12月, 優秀講演賞, 高飽和磁化を有する垂直磁気異方性膜の作製, 電気学会東京支部茨城支所発表会
在原康貴,小峰啓史,杉田龍二
国内学会・会議・シンポジウム等の賞

〔主要な業績〕Composition dependence of anomalous Nernst effect in amorphous TbFeCo thin films with perpendicular magnetic anisotropy
R. Ando; and T. Komine, ラスト(シニア)オーサー, AIP
J. Appl. Phys., 2024年03月, ［査読有り］

Microwave Transmission Theory for On-Chip Ultrastrong-Coupled Magnon-Polariton in Dynamical Inductors
T. Chiba; T. Komine; and T. Aono
J. Magn. Soc. Jpn., 2024年03月, ［査読有り］

〔主要な業績〕Magnetic printing characteristics of burst signals by using double magnet master media　　　　　　　　　　　　　　　
T. Komine, 筆頭著者, AIP
AIP advances, 2024年03月, ［査読有り］

〔主要な業績〕Fully micromagnetic analysis of voltage-controlled magnetization switching in magnetic-topological-insulator-based devices
T. Komine; and T. Chiba, 筆頭著者, AIP
AIP advances, 2024年02月, ［査読有り］

Ultrastrong-coupled magnon–polariton in a dynamical inductor based on magnetic-insulator/topological-insulator bilayers
Takahiro Chiba; Takashi Komine; Tomosuke Aono, We theoretically study a magnon–polariton in a dynamical inductor consisting of a coil and a bilayer of ferromagnetic insulator (FI) with perpendicular magnetization and a three-dimensional topological insulator (TI). Taking into account the coherent magnetic-dipole (Zeeman) interaction as well as the dissipative spin pumping effect on the FI/TI interface, we formulate a dynamical permeability of the FI/TI bilayer and calculate a corresponding electric admittance of an RLC-circuit. As a result, the spin pumping gives rise to a competitive effect on the modes hybridization, whereas a huge level repulsion due to the coherent coupling, which reaches the ultrastrong coupling regime, is found at room temperature for realistic parameter sets. Our work may open a new avenue for designing on-chip microwave devices based on a magnon–polariton in the RLC-circuit., AIP Publishing
Applied Physics Letters, 2024年01月, ［査読有り］

Bi-Sbにおける磁場中熱電物性の同一試料測定と試料形状の影響
村田正行; 鈴木真理; 青山佳代; 長瀬和夫; 大島博典; 山本淳; 長谷川靖洋; 小峰啓史, ラスト(シニア)オーサー
日本熱電学会誌, 2023年10月, ［査読有り］

Numerical analysis of voltage-controlled magnetization switching operation in magnetic-topological-insulator-based devices
Takashi Komine; Takahiro Chiba, 筆頭著者, We theoretically investigate influences of electronic circuit delay, noise, and temperature on write-error-rate (WER) in voltage-controlled magnetization switching operation of a magnetic-topological-insulator-based device by means of the micromagnetic simulation. This device realizes magnetization switching via spin–orbit torque (SOT) and voltage-controlled magnetic anisotropy (VCMA), which originate from the 2D-Dirac electronic structure. We reveal that the device operation is extremely robust against circuit delay and signal-to-noise ratio. We demonstrate that the WER on the order of ∼10−4 or below is achieved around room temperature due to steep change in VCMA. Also, we show that the larger SOT improves thermal stability factor. This study provides a next perspective for developing voltage-driven spintronic devices with ultra-low power consumption., AIP Publishing
Applied Physics Letters, 2023年09月, ［査読有り］

Write-error rate estimation of voltage-controlled magnetization switching in a magnetic-topological-insulator-based device
Takashi Komine; Shimon Watahiki; Takahiro Chiba, IEEE
2023 IEEE International Magnetic Conference - Short Papers (INTERMAG Short Papers), 2023年05月

Temperature profile of the Thomson-effect-induced heat release/absorption in junctionless single conductors
Takahiro Chiba; Ryo Iguchi; Takashi Komine; Yasuhiro Hasegawa; Ken-ichi Uchida, Abstract

The Thomson effect induces heat release or absorption under the simultaneous application of a charge current and a temperature gradient to conductors. Here, we theoretically investigate the temperature profile due to the Thomson-effect-induced heat release/absorption in junctionless single conductors which can be a simple temperature modulator. We also perform analysis of the temperature profile for realistic conductors. As a result, we find that, for a conductor with a large Thomson coefficient, the temperature derivative of the Seebeck coefficient, the Thomson-effect-induced heat absorption overcomes the Joule heating, resulting in current-induced cooling in the bulk region. We also elucidate that a feedback effect of the Thomson effect stabilizes the system temperature to one-side of the heat bath, which reflects the fact that the Thomson effect is dependent on the position and proportional to the local temperature gradient. This work will be the basis for thermal management utilizing the Thomson effect., IOP Publishing
Japanese Journal of Applied Physics, 2023年03月

〔主要な業績〕Combinatorial dependence of magnetic printing characteristics in double magnet master media for energy-assisted magnetic recording
T. Komine, 筆頭著者, AIP
AIP advances, 2023年02月, ［査読有り］

Room-temperature magnetoresistance in Ni₇₈Fe₂₂/C8-BTBT/Ni₇₈Fe₂₂ nanojunctions fabricated from magnetic thin-film edges using a novel technique
M. Matsuzaka; Y. Sasaki; K. Hayashi; T. Misawa; T. Komine; T. Akutagawa; M. Fujioka; J. Nishii; H. Kaiju, The paper presents room-temperature magnetoresistance in molecular spintronic nanodevices fabricated using magnetic thin-film edges., The Royal Society of Chemistry
Nanoscale Advances, 2022年10月, ［査読有り］

〔主要な業績〕Master structure dependence of double magnet master on magnetic printing performance onto energy-assisted magnetic recording media
T. Komine, マスター構造，特にDMMで重要な非磁性分離層が及ぼす影響を議論した．結果として，非磁性分離層厚および磁性膜厚を最適化することで，さらなる特性が改善が示唆された．, IEEE
IEEE Trans. Magn., 2022年01月, ［査読有り］

〔主要な業績〕Novel technique for controlling anisotropic ion diffusion: bulk single-crystalline metallic silicon clathrate
S Iwasaki; H. Morito; T. Komine; K. Morita; T. Shibuya; J. Nishii; M. Fujioka, Na-free Si clathrates consisting only of Si cages are an allotrope of diamond-structured Si. This material is promising for various device applications, such as next-generation photovoltaics. The probable technique for synthesizing Na-free Si clathrates is to extract Na+ from the Si cages of Na24Si136. Vacuum annealing is presently a well-known conventional and effective approach for extracting Na. However, this study demonstrates that Na+ cannot be extracted from the surface of a single-crystalline type-II metallic Si clathrate (Na24Si136) in areas deeper than 150 µm. Therefore, a novel method is developed to control anisotropic ion diffusion: this is effective for various compounds with a large difference in the bonding strength between their constituent elements, such as Na24Si136 composed of covalent Si cages and weakly trapped Na+. By skillfully exploiting the difference in the chemical potentials as a driving force, Na+ is homogeneously extracted regardless of the size of the single crystal while maintaining high crystallinity. Additionally, the proposed point defect model is evaluated via density functional theory, and the migration of Na+ between the Si cages is explained. It is expected that the developed experimental and computational techniques would significantly advance material design for synthesizing thermodynamically metastable materials., Wiley
Adv. Mater., 2021年12月, ［査読有り］

〔主要な業績〕Voltage-control of damping constant in magnetic–insulator/topological–insulator bilayers
T. Chiba; A. O. Leon; T. Komine, ラスト(シニア)オーサー, AIP Publishing
Appl. Phys. Lett., 2021年07月, ［査読有り］

〔主要な業績〕Double magnet master media for magnetic printing onto energy-assisted magnetic recording media
T. Komine, IEEE
IEEE Trans. Magn., 2021年05月, ［査読有り］

Anomalous Nernst and Seebeck Effects in NiCo₂O₄ Films
H. Koizumi; A. Hidaka; T. Komine; H. Yanagihara
J. Magn. Soc. Jpn., 2021年01月, ［査読有り］

Thermoelectric refrigerator based on asymmetric surfaces of a magnetic topological insulator
T. Chiba; T. Komine, AIP Publishing
AIP advances, 2020年12月, ［査読有り］

Voltage-driven magnetization switching via Dirac magnetic anisotropy and spin-orbit torque in topological-insulator-based magnetic heterostructures
T. Chiba; T. Komine, ラスト(シニア)オーサー
Phys. Rev. Appl., 2020年09月, ［査読有り］

Electrical fluctuation spectra due to characteristic thermal diffusion in Ta thin films deposited by RF-magnetron sputtering
R. Uesugi; T. Komine; M. Mizuno; R. Ando; H. Akabane, 責任著者, IOP Publishing
Jpn. J. Appl. Phys., 2020年02月, ［査読有り］

First Principle Band Calculations of Mg₂Si Thin Films with (001) and (110) Orientations
M. Takizawa; T. Komine; H. Udono; T. Aono
JJAP Conf. Proc., 2019年09月, ［査読有り］

Ambipolar Seebeck power generator based on topological insulator surfaces
T. Chiba; S. Takahashi; T. Komine
Appl. Phys. Lett., 2019年08月, ［査読有り］

Robustness of Voltage-induced Magnetocapacitance
H. Kaiju; T. Misawa; T. Nagahama; T. Komine; O. Kitakami; M. Fujioka; J. Nishii; G. Xiao, One of the most important achievements in the field of spintronics is the development of magnetic tunnel junctions (MTJs). MTJs exhibit a large tunneling magnetoresistance (TMR). However, TMR is strongly dependent on biasing voltage, generally, decreasing with applying bias. The rapid decay of TMR was a major deficiency of MTJs. Here we report a new phenomenon at room temperature, in which the tunneling magnetocapacitance (TMC) increases with biasing voltage in an MTJ system based on Co40Fe40B20/Mgo/Co40Fe40B20 . We have observed a maximum TMC value of 102% under appropriate biasing, which is the largest voltage-induced TMC effect ever reported for MTJs. We have found excellent agreement between theory and experiment for the bipolar biasing regions using Debye-Frohlich model combined with quartic barrier approximation and spin-dependent drift-diffusion model. Based on our calculation, we predict that the voltage-induced TMC ratio could reach 1100% in MTJs with a corresponding TMR value of 604%. Our work has provided a new understanding on the voltage-induced AC spin-dependent transport in MTJs. The results reported here may open a novel pathway for spintronics applications, e.g., non-volatile memories and spin logic circuits., Springer Nature Limited
Scientific reports, 2018年10月, ［査読有り］

Novel behaviors of anomalous Hall effect in TbFeCo ferrimagnetic thin films
Ryo Ando; Takashi Komine; Shiori Sato; Shingo Kaneta; Yoshiaki Hara, We investigate the temperature dependence and the thickness dependence of anomalous Hall effect (AHE) of TbFeCo ultra-thin films under high magnetic field. The sign change on temperature dependence of AHE in 20nm-thick TbFeCo film with rare-earth (RE) rich composition was observed. The AHE sign at low temperature is negative while it gradually becomes positive as the temperature increases. Moreover, the AHE sign for 5nm-thick TbFeCo film remains positive while that for 50nm-thick TbFeCo film remains negative at temperature in the range from 5 K to 400 K. The similar thickness dependence of AHE in TM-rich samples was also observed. From the mean-field approximation, the sign change temperature in AHE is related to the compensation temperature and the existence of interfacial region, which has the TM-rich composition and the weak anisotropy. Therefore, We clarified that the novel behavior of AHE sign changes in TbFeCo thin films with different thickness can be explained by the interfacial layer with weak anisotropy and two phase model., American Institute of Physics Inc.
AIP Advances, 2018年05月, ［査読有り］

Geometrical contribution to the anomalous Nernst effect in TbFeCo thin films
Ryo Ando; Takashi Komine, The geometrical contribution to the anomalous Nernst effect in magnetic thin films was experimentally investigated by varying the aspect ratios and electrode configurations. The bar-Type electrode configuration induces a short-circuit current near both edges of electrodes and decreases the effective Nernst voltage, while the point-contact (PC) electrode exploits the intrinsic Nernst voltage. In a sample with PC electrodes, as the sample width along the transverse direction of the thermal flow increases, the Nernst voltage increases monotonically. Thus, a much wider element with PC electrodes enables us to bring out a larger Nernst voltage by utilizing perpendicularly magnetized thin films., American Institute of Physics Inc.
AIP Advances, 2018年05月, ［査読有り］

面内磁場下の量子ポイントコンタクトにおける動的核スピン偏極
青野 友祐; 川村 稔; 大野 圭司; 小峰 啓史, 一般社団法人 日本物理学会
日本物理学会講演概要集, 2018年

Fabrication of a Nanoscale Electrical Contact on a Bismuth Nanowire Encapsulated in a Quartz Template by Using FIB-SEM
Masayuki Murata; Atsushi Yamamoto; Yasuhiro Hasegawa; Takashi Komine, A method to fabricate an electrode on a 110-nm-diameter Bi nanowire, encapsulated in a quartz template, was established using a dual beam instrument equipped with a focused ion beam and a scanning electron microscope. A fabrication method has already been successfully developed to obtain suitable Ohmic contact on both ends of Bi nanowires (several hundred nanometers in diameter) by first polishing the ends of the nanowires, and then depositing titanium/copper thin-films via an ion-plating method. However, with this method, it was difficult to obtain suitable electrodes on Bi nanowires with diameters less than 300 nm. Therefore, in order to understand why it was not possible to establish an electrical contact in small-diameter Bi nanowires, the vertical section of the fabricated electrode and the end of a 110-nm-diameter Bi nanowire were observed using a focused ion beam scanning electron microscope. A vacant area was observed between the end of the nanowire and the titanium thin-film, indicating a possible cause for the electrical contact failure. This implies that the quartz-encapsulated Bi nanowire is selectively removed when it undergoes polishing due to the great difference in hardness between Bi and quartz. A local electrode, which would connect the exposed area of the Bi nanowire and the metal thin-films on the surface of the quartz template, was fabricated by tungsten deposition using an electron beam. After fabrication of the opposite-end electrode by the same method, an electrical connection was successfully confirmed by measuring the voltage between both ends of the metal thin-films with a circuit tester. Ohmic contact was confirmed by measuring the current-voltage characteristics between the fabricated electrodes. As a result, the electrical resistivity and Seebeck coefficient were successfully measured at 300 K., SPRINGER
JOURNAL OF ELECTRONIC MATERIALS, 2017年05月, ［査読有り］

Experimental and theoretical evaluations of the galvanomagnetic effect in an individual bismuth nanowire
Masayuki Murata; Atsushi Yamamoto; Yasuhiro Hasegawa; Takashi Komine, The galvanomagnetic effect is evaluated experimentally and theoretically in an individual bismuth nanowire encapsulated within a quartz template. A small section of the side surface of the encapsulated bismuth nanowire is exposed using focused ion beam processing, and a total of six carbon film electrodes are fabricated on the exposed nanowire surface by in situ deposition in order to be able to perform electrical measurements on the nanowire. The results show that the galvanomagnetic effect in the nanowire is affected by carrier collisions at the nanowire boundary
this is particularly the case at low temperatures. The Hall mobilities of electrons and holes are determined based on the measured Hall coefficient and magnetoresistivity values. It is found that the carrier mobility in the bismuth nanowire is lower than that in bulk bismuth and that it plateaus at low temperatures, as predicted by the calculation model used in the study, which takes into account the carrier mean free path limitation imposed by the small diameter of the nanowire., American Chemical Society
Nano Letters, 2017年, ［査読有り］

Theoretical modeling of electrical resistivity and Seebeck coefficient of bismuth nanowires by considering carrier mean free path limitation
Masayuki Murata; Atsushi Yamamoto; Yasuhiro Hasegawa; Takashi Komine; Akira Endo, In this study, the electrical resistivity and Seebeck coefficient of bismuth nanowires, several hundred nanometers in diameter, are calculated using the Boltzmann equation in the relaxation time approximation. The three-dimensional density of states and properties of single-crystalline bulk bismuth, such as carrier density, effective mass, and mobility, are used in the calculation without considering the quantum size effect. The relaxation times of the electrons and holes are calculated using Matthiessen's rule considering the carrier collisions at the wire boundary. The temperature, crystal orientation, and diameter dependence of the electrical resistivity and Seebeck coefficient are investigated. The calculation demonstrates that the electrical resistivity increases gradually with decreasing wire diameter, and the temperature coefficient of the electrical resistivity varies from positive to negative at low temperatures for thin wires with diameters less than approximately 500 nm. The diameter dependence of the electrical resistivity varies with the crystal orientation; the increase along the bisectrix axis is larger than that along the binary and trigonal axes. The temperature dependence of the Seebeck coefficient also strongly depends on the crystal orientation. The absolute value of the negative Seebeck coefficient along the bisectrix axis rapidly decreases with decreasing diameter and even changes sign from negative to positive at low temperatures despite the charge neutrality condition, while the Seebeck coefficients along the binary and trigonal axes do not differ significantly from those of single-crystalline bulk bismuth. We conclude that the thermoelectric properties of bismuth nanowires strongly depend not only on the wire diameter but also on the crystal orientation. Published by AIP Publishing., AMER INST PHYSICS
JOURNAL OF APPLIED PHYSICS, 2017年01月, ［査読有り］

Structural and magnetic properties of Ni78Fe22 thin films sandwiched between low-softening-point glasses and application in spin devices
Takahiro Misawa; Sumito Mori; Takashi Komine; Masaya Fujioka; Junji Nishii; Hideo Kaiju, We investigate the structural and magnetic properties of Ni78Fe22 thin films sandwiched between low softening-point (LSP) glasses, which can be used in spin quantum cross (SQC) devices utilizing stray magnetic fields generated from magnetic thin-film edges. We also calculate the stray magnetic field generated between the two edges of Ni78Fe22 thin-film electrodes in SQC devices and discuss the applicability to spin-filter devices. Using the established fabrication technique, we successfully demonstrate the formation of LSP-glass/Ni78Fe22/LSP-glass structures with smooth and clear interfaces. The coercivity of the Ni78Fe22 thin films is enhanced from 0.9 to 103 Oe by increasing the applied pressure from 0 to 1.0 MPa in the thermal pressing process. According to the random anisotropy model, the enhancement of the coercivity is attributed to the increase in the crystal grain size. The stray magnetic field is also uniformly generated from the Ni78Fe22 thin-film edge in the direction perpendicular to the cross section of the LSP-glass/Ni78Fe22/LSP-glass structures. Theoretical calculation reveals that a high stray field of approximately 5 kOe is generated when the distance between two edges of the Ni78Fe22 thin-film electrodes is less than 5 nm and the thickness of Ni78Fe22 is greater than 20 nm. These experimental and calculation results indicate that Ni78Fe22 thin films sandwiched between LSP glasses are useful as electrodes for SQC devices, serving as spin-filter devices. (C) 2016 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE BV
APPLIED SURFACE SCIENCE, 2016年12月, ［査読有り］

Giant thermoelectric figure of merit in a noninteracting quantum dot system with massless Dirac fermions
Tomosuke Aono; Takashi Komine, We investigate the thermoelectric characteristics of a quantum dot system with massless Dirac fermions, in which the tunneling coupling between the quantum dot and the Dirac fermions has a pseudogap. The maximum values of the thermoelectric figure of merit and the thermopower can be made independent of temperature by tuning the energy level of the dot; the maximum value of the thermoelectric figure of merit is much greater than unity, and that of the thermopower is approximately 500 mu V/K. These characteristics also appear when the distance from the Dirac point to the Fermi level is lower than the thermal energy., AMER PHYSICAL SOC
PHYSICAL REVIEW B, 2016年10月, ［査読有り］

Anomalous Nernst Effect of Perpendicularly Magnetic Anisotropy TbFeCo Thin Films
Ryo Ando; Takashi Komine; Yasuhiro Hasegawa, In this study, we investigated anomalous Nernst effect (ANE) of perpendicularly magnetized TbFeCo thin films with various Tb content, and especially studied the relation between ANE and anomalous Hall effect. As a result, the hysteresis of anomalous Nernst coefficient showed the same behavior as that of anomalous Hall resistivity, and the sign of anomalous Nernst coefficient was consistent with that of anomalous Hall voltage in any Tb content, whereas the Seebeck coefficient and the resistivity were almost constant even if the applied magnetic field was varied. Taking into account of thermoelectric coefficient tensor, it was revealed that the off-diagonal thermopower corresponding to the ANE in TbFeCo thin films is the product of Hall angle and Seebeck coefficient., SPRINGER
JOURNAL OF ELECTRONIC MATERIALS, 2016年07月, ［査読有り］

Micromagnetic analysis of current-induced domain wall motion in a bilayer nanowire with synthetic antiferromagnetic coupling
Takashi Komine; Tomosuke Aono, We demonstrate current-induced domain wall motion in bilayer nanowire with synthetic antiferromagnetic (SAF) coupling by modeling two body problems for motion equations of domain wall. The influence of interlayer exchange coupling and magnetostatic interactions on current-induced domain wall motion in SAF nanowires was also investigated. By assuming the rigid wall model for translational motion, the interlayer exchange coupling and the magnetostatic interaction between walls and domains in SAF nanowires enhances domain wall speed without any spin-orbit-torque. The enhancement of domain wall speed was discussed by energy distribution as a function of wall angle configuration in bilayer nanowires. (C) 2016 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License., AMER INST PHYSICS
AIP ADVANCES, 2016年05月, ［査読有り］

Magnetic-Field Dependence of Thermoelectric Properties of Sintered Bi90Sb10 Alloy
Masayuki Murata; Atsushi Yamamoto; Yasuhiro Hasegawa; Takashi Komine, The magnetic-field dependence of the thermoelectric properties and dimensionless figure of merit (ZT) of a sintered Bi90Sb10 alloy were experimentally and theoretically evaluated. The Bi-Sb alloy was synthesized in a quartz ampule using the melting method, and the resultant ingot was then ground via ball milling. A sintered Bi90Sb10 alloy with a particle size in the range of several to several tens of micrometers was prepared using the spark plasma sintering (SPS) method. The magnetic-field dependence of the electrical resistivity, Seebeck coefficient, and thermal conductivity were experimentally evaluated at temperatures of 77-300 K for magnetic fields of up to 2.9 T. The results showed that ZT increased by 37% at 300 K under a 2.5-T magnetic field. A theoretical calculation of the magneto-Seebeck coefficient based on the Boltzmann equation with a relaxation time approximation was also performed. Hence, the experimental result for the magneto-Seebeck coefficient of the Bi90Sb10 alloy at 300 K was qualitatively and quantitatively explained. Specifically, the carrier scattering mechanism was shown to be acoustic phonon potential scattering and the carrier mobility ratio between the L-and T-points was found to be 3.3, which corresponds to the characteristics of a single crystal. It was concluded that the effect of the magnetic field on the Seebeck coefficient was demonstrated accurately using the theoretical calculation model., SPRINGER
JOURNAL OF ELECTRONIC MATERIALS, 2016年03月, ［査読有り］

Enhancement of Seebeck Coefficient in Bi Nanowires by Electric Field Effect
Takashi Komine; Tomosuke Aono; Yuta Nabatame; Masayuki Murata; Yasuhiro Hasegawa, In this study, we investigated the electric field effect on the transport properties of a Bi nanowire. These effects were modeled by a surface potential. The electron states of Bi nanowires were numerically analyzed by effective mass equations at the T-point and L-point taking into account surface potential due to an external electric field. The Seebeck coefficients of Bi nanowires were calculated by using the Boltzmann equation with a constant relaxation time. It was found that the Seebeck coefficients increased when the sign of the surface potential parameter was negative. In particular, when the surface potential parameter was -1 eV and the skin depth was 10 nm in a 20-nm-diameter nanowire, the maximum absolute value of the Seebeck coefficient was larger than 1 mV/K, which was greatly improved compared to that without an external electric field., SPRINGER
JOURNAL OF ELECTRONIC MATERIALS, 2016年03月, ［査読有り］

Tight-binding theory of surface spin states on bismuth thin films
Kazuo Saito; Hirokatsu Sawahata; Takashi Komine; Tomosuke Aono, The surface spin states for bismuth thin films are investigated using an sp(3) tight-binding model. The model explains most experimental observations using angle-resolved photoemission spectroscopy, including the Fermi surface, the band structure with Rashba spin splitting, and the quantum confinement in the energy band gap of the surface states. A large out-of-plane spin component also appears. The surface states penetrate inside the film to within approximately a few bilayers near the Brillouin-zone center, whereas they reach the center of the film near the Brillouin-zone boundary., AMER PHYSICAL SOC
PHYSICAL REVIEW B, 2016年01月, ［査読有り］

Influence of classical electromagnetic effect on current-induced domain wall motion in a perpendicularly magnetized nanowire　　　　　　　　　　　　　　　
T. Komine; T. Aono; R. Ando
J. Appl. Phys., 2015年04月, ［査読有り］

Co thickness dependence of structural and magnetic properties in spin quantum cross devices utilizing stray magnetic fields　　　　　　　　　　　　　　　
H. Kaiju; H. Kasa; T. Komine; T. Abe; S. Mori; T. Misawa; J. Nishii
J. Appl. Phys., 2015年04月, ［査読有り］

Simultaneous measurement of the Seebeck coefficient and thermal diffusivity for bulk thermoelectric materials
R. Homma; Y. Hasegawa; H. Terakado; H. Morita; T. Komine, We simultaneously measured the Seebeck coefficient and thermal diffusivity of a rectangular parallelepiped bulk thermoelectric material. We used one-dimensional heat conduction equation to show that a periodic heat cycle produces not only the thermoelectromotive force but also a certain phase shift angle between the edge and intermediate points of a sample along the length of the material. Based on the equation of the modified Angström method, an experiment at 300 K was performed using NIST standard material (SRM 3451, Bi2Te3material) to measure the Seebeck coefficient and thermal diffusivity. The measured Seebeck coefficient was −231 ± 3 µV/K, which corresponds to the published value. Using the same experimental setup as that for the thermal diffusivity measurement, the dependence of the phase shift angle on frequency was measured from 5 mHz to 10 Hz for the phase shift angle from −8.2 to −450°. The estimated thermal diffusivity was (1.53 ± 0.05) × 10⁻⁶m²/s. We conclude that the modified Angström method can be used to measure the Seebeck coefficient and thermal diffusivity simultaneously., Institute of Physics
Jpn. J. Appl. Phys., 2015年01月, ［査読有り］

Magnetic properties of spin quantum cross devices utilizing stray magnetic fields
Hideo Kaiju; Haruya Kasa; Takashi Komine; Taro Abe; Takahiro Misawa; Junji Nishii, We investigate structural and magnetic properties of Co thin-film electrodes used in a new type of spin quantum cross (SQC) devices, in which a strong stray magnetic field could be generated between the both edges of magnetic thin-film electrodes. We also calculate the stray field between the two edges of Co thin-film electrodes in SQC devices and discuss the possibility to novel spintronics devices. As a result of magnetic force microscopy (MFM) observations, the stray fields are generated from the Co edges, and they are uniformly distributed. This result indicates that magnetic single-domain structures can be formed. This is consistent with the result obtained by magneto-optical Kerr effect (MOKE). The theoretical calculation reveals that the stray field exhibits as high as 7000 Oe under the condition that the distance between the two Co edges is 5 nm and the Co thickness is 19 nm. These results indicate that SQC devices utilizing stray fields can be expected as novel spintronics devices, such as spin filtering devices and beyond CMOS switching devices., Materials Research Society
Materials Research Society Symposium Proceedings, 2014年, ［査読有り］

Micromagnetic Study of Influence of Gd Content on Current-Induced Domain Wall Motion in a Ferrimagnetic Nanowire
Jo Kajitani; Takashi Komine; Ryuji Sugita, In this study, the influence of Gd composition on current-induced domain wall motion in a Gd-Co ferrimagnetic nanowire was theoretically investigated with taking into account of composition dependence of magnetic properties. As a result, the intrinsic critical density to move domain wall significantly reduces near the compensation composition, which is achieved to be less than 10(5) A/cm(2). Moreover, the intrinsic critical current density also significantly reduces near a certain Gd composition where the domain wall energies of Bloch and Neel walls are almost the same., IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG
IEICE TRANSACTIONS ON ELECTRONICS, 2013年12月

Dependence of hard-axis anisotropy field on domain wall width for current-induced domain wall motion in nanowires
Makoto Ito; Ayaka Ooba; Takashi Komine; Ryuji Sugita, The dependence of the hard-axis anisotropy field on the domain wall width for current-induced domain wall motion in perpendicularly magnetized anisotropic nanowires was investigated using micromagnetic simulations. The hard-axis anisotropy field in nanowires was estimated by varying the magnetic anisotropy constant and the exchange stiffness constant, and the hard-axis anisotropy constant was calculated from the energy differences of the Bloch and Neel walls. As a result, when the stable domain wall is a Bloch wall, the hard-axis anisotropy field and the intrinsic critical current velocity decrease with increasing domain wall width, whereas when the stable domain wall is a Neel wall, they increase with increasing domain wall width. It was clarified that the intrinsic critical current velocity can be expressed as a function of the domain wall width, even though the analytical solution indicated that the critical current velocity would be monotonically reduced by decreasing the domain wall width. (C) 2013 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE BV
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 2013年08月

Micromagnetic Study on Influence of the Magnetic Field Direction on the Domain Structure in Stacked Media
Y. Yamaguchi; S. Sato; S. Kumagai; T. Komine; R. Sugita, The relation between the domain structure in stacked media and applied magnetic field direction was investigated by using micromagnetic simulation assuming that the interlayer exchange constant between the hard and soft layers changes depending on the direction of the magnetization. The interlayer exchange constant was set to maximum and minimum for the magnetization in perpendicular and in-plane direction, respectively. As a result, it was clarified that the stacked medium demagnetized with perpendicular field had simple domain structure, while that demagnetized with in-plane field consisted of domains including sub-domains in them. The stray field distribution from the calculated magnetization distribution almost coincided with the results of the MFM observation, namely, the amplitude of the field variation for the in-plane demagnetized medium was about half of that for the perpendicularly demagnetized medium and the cycle of the field variation for the in-plane and the perpendicularly demagnetized medium was almost equal., IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
IEEE TRANSACTIONS ON MAGNETICS, 2013年07月, ［査読有り］

Thermal conductivity of an individual bismuth nanowire covered with a quartz template using a 3-omega technique　　　　　　　　　　　　　　　
Y. Hasegawa; M. Murata; F. Tsunemi; Y. Saito; K. Shirota; T. Komine; C. Dames; J. E. Garay
J. Elec. Mater., 2013年06月, ［査読有り］

Dependence of Temperature Coefficient of Electrical Resistivity on Individual and Single-Crystal Bismuth Nanowires　　　　　　　　　　　　　　　
M. Murata; F. Tsunemi; Y. Saito; K. Shirota; K. Fujiwara; Y. Hasegawa; T. Komine
J. Elec. Mater., 2013年06月, ［査読有り］

Numerical analysis of boundary scattering effect on transport properties in a Bi-Sb nanowire　　　　　　　　　　　　　　　
Y. Nabatame; T. Matsumoto; Y. Ichige; T. Komine; R Sugita; M. Murata; Y. Hasegawa
J. Elec. Mater., 2013年06月, ［査読有り］

Micromagnetic study of novel domain wall motion modes in bilayer nanowire with low saturation magnetization
A. Ooba; T. Komine; R. Sugita, In this study, the effect of the magnetostatic interaction in the bilayer nanowires with perpendicular magnetic anisotropy and low saturation magnetization on the current-induced domain wall motion has been investigated by using micromagnetic calculation. The bilayer nanowire, which consists of continuous layer (CL) and granular layer (GL), is used, and the saturation magnetization in each layer is varied. As a result, domain walls in CL and GL move together as the domain wall structure and the velocities vary. The domain wall motion in bilayer nanowires can be divided into two modes. In one mode, the velocity of domain wall varies when the domain wall structure switches between Bloch and Neel walls. In the other mode, the velocity of domain wall varies when the domain wall structure switches between 90 degrees and 270 degrees of Neel walls. Moreover, the critical current velocity, which corresponds to the spin transfer velocity in the bilayer nanowires, increases with increasing saturation magnetization of the continuous layer and the granular layer. This is because the total energy difference which is the energy difference between two extreme values in total energy as a function of magnetization angle at wall and is proportional to the hard-axis anisotropy energy increases with increasing saturation magnetization of the continuous layer and the granular layer. (C) 2013 AIP Publishing LLC., AMER INST PHYSICS
JOURNAL OF APPLIED PHYSICS, 2013年05月, ［査読有り］

Shubnikov--de Haas Oscillations in Single-Crystal Bismuth Nanowires Encased in Quartz Template
Tsunemi Fumiaki; Murata Masayuki; Saito Yusuke; Shirota Katsuhito; Hasegawa Yasuhiro; Komine Takashi, Shubnikov--de Haas (SdH) oscillations were measured at 0.3 K in bismuth nanowires with diameters of 393, 548, and 622 nm, and lengths of over 1 mm, which were encased in quartz templates. The magnetoresistance was measured up to a magnetic field of 17 T. Distinct SdH oscillations were observed, and the nanowire samples were rotated in the magnetic field to determine the contribution due to holes, electrons, and spin--orbit interactions. For the 622-nm-diameter nanowire, for example, values of 30.7 meV and 1.66\times 10^{17} cm^-3were obtained for the Fermi energy and carrier density, respectively, which were similar to the values for bulk bismuth., The Japan Society of Applied Physics
Applied physics express, 2013年04月

CoPt垂直磁気異方性膜の磁区構造
川田裕介,東條隆介,佐藤翔平,小峰啓史,杉田龍二,, 日本磁気学会
J. Magn. Soc. Jpn., 2013年03月, ［査読有り］

Effect of Applied Magnetic Field Direction on Magnetic Cluster State of Perpendicular Recording Media
S. Sato; Y. Yamaguchi; T. Komine; R. Sugita, We investigated influence of applied magnetic field direction on magnetic cluster state of perpendicular recording media. As a result, cluster size estimated from MFM images did not change as the applied field angle changed. On the other hand, it was clarified that the stray field from the media decreased as the applied field angle from the perpendicular direction increased. The decrease of the stray field is presumed to originate from magnetic cluster including subdomains less than MFM resolution., IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
IEEE TRANSACTIONS ON MAGNETICS, 2012年11月, ［査読有り］

Influence of Interlayer Coupling on Current-Induced Domain Wall Motion in Multilayered Nanowires
A. Ooba; T. Komine; R. Sugita, In this study, influence of interlayer exchange coupling on current-induced domain wall motion in multilayered nanowires for achieving high density bit has been analyzed by using micromagnetic simulation. As a result, the domain walls in the continuous and the granular layers move all together even if the interlayer exchange coupling is 0 erg/cm. The domain wall velocity increases with increasing interlayer exchange coupling. The total energy difference between Neel walls increases with increasing domain wall width due to the magnetostatic field generated from the granular layer., IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
IEEE TRANSACTIONS ON MAGNETICS, 2012年11月, ［査読有り］

積層構造垂直磁気異方性マスター媒体による垂直磁気転写
川崎龍太,小野瀬勝,大山哲広,川田裕介,小峰啓史,杉田龍二,,   A multi-layered master medium with perpendicular anisotropy is proposed. The multi-layered master medium is composed of a thin CoPt film with perpendicular magnetic anisotropy, a nonmagnetic interlayer with several nanometers in thickness, and a soft magnetic FeCo-based film. Magnetic printing characteristics by using single-layered and multi-layered master media were investigated through experiments. The best magnetic printing characteristics were obtained by using the multi-layered master medium. This is because the multi-layered master medium has larger recording field than the single-layered master media near side wall of convex part due to high perpendicular anisotropy of the CoPt film and image effect by the soft magnetic film., 公益社団法人 日本磁気学会
J. Magn. Soc. Jpn., 2012年10月, ［査読有り］

Effect of a Pinning Field on the Critical Current Density for Current-Induced Domain Wall Motion in Perpendicular Magnetic Anisotropy Nanowires
Ayaka Ooba; Yuma Fujimura; Kota Takahashi; Takashi Komine; Ryuji Sugita, In this study, the effect of a pinning field on the critical current density for current-induced domain wall motion in nanowires with perpendicular magnetic anisotropy was investigated using micromagnetic simulations. In order to estimate the pinning field in notched nanowires, we conducted wall energy calculations for nanowires with various saturation magnetizations. The pinning field increased as the notch size increased. The pinning field decreased as the saturation magnetization decreased. As a result, the decreased in the pinning field causes the reduction of the critical current density. Therefore, a significant reduction of the critical current density can be obtained by decreasing the saturation magnetization, even if wall pinning occurs., AMER SCIENTIFIC PUBLISHERS
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY, 2012年09月, ［査読有り］

Preparation of bismuth nanowire encased in quartz template for Hall measurements using focused ion beam processing
Masayuki Murata; Yasuhiro Hasegawa; Takashi Komine; Tomohiro Kobayashi, Forming electrodes on opposite sides of an individual bismuth nanowire was attempted to prepare for Hall measurements. Although a 1-mm-long bismuth nanowire which is completely covered with a quartz template has been successfully fabricated to prevent oxidation, it is very difficult to attach Hall electrodes on the opposite sides of the nanowire due to the quartz covering. One side of the cylindrical quartz template was removed by polishing without exposure of the nanowire to the atmosphere; the thickness between the polished template surface and the nanowire was estimated to be several micrometers. Focused ion beam processing was successfully employed to expose both surfaces of the nanowire under high vacuum by removing part of the quartz template. A carbon thin film was then deposited in situ on the wire surface to fabricate an electrical contact on the bismuth nanowire sample. Furthermore, the energy dispersive X-ray analysis was performed to the area processed by focused ion beam, and the bismuth component of the nanowire was successfully detected. It was confirmed that the focused ion beam processing was applicable to attach electrodes to bismuth nanowire for Hall measurement., SPRINGER
NANOSCALE RESEARCH LETTERS, 2012年09月

Four-Wire Resistance Measurements of a Bismuth Nanowire Encased in a Quartz Template Utilizing Focused Ion Beam Processing
Masayuki Murata; Hiroya Yamamoto; Fumiaki Tsunemi; Yasuhiro Hasegawa; Takashi Komine, Four-wire resistance measurements were performed using a bismuth nanowire, 750 nm in diameter, 1.96 mm in length, and encapsulated in a quartz template. One side of the quartz template was polished to allow focused ion beam (FIB) processing, and metal film layers were deposited on the polished side to form electrodes. Nanofabrication was employed to remove a selected portion of the quartz, and FIB processing was used to expose the surface of the bismuth nanowire. A local area of the bismuth wire was successfully exposed, and a carbon electrode was deposited on the bismuth wire by a chemical reaction between the ion beam and phenanthrene gas. Additional carbon deposition on the initial carbon electrode was used to connect to a metal film on the quartz template. In total, four nanofabrications were performed on the bismuth wire to create the desired electrical contacts. The resistivity of the nanowire was measured by a four-wire method to be 1.29 Omega m at 300 K, corresponding to that of bulk bismuth. The temperature dependence of the resistivity was also measured, and was qualitatively and quantitatively in good agreement with previous calculated and experimental results using other bismuth nanowires. The present results demonstrate the successful development of a technique to fabricate an electrode on a local area of a nanowire using FIB processing to form suitable electrical contacts., SPRINGER
JOURNAL OF ELECTRONIC MATERIALS, 2012年06月, ［査読有り］

ECC媒体におけるクロストラック方向の磁気転写特性
川前武士,小峰啓史,杉田龍二, Magnetic printing characteristics along the cross-track direction on ECC media were investigated by using micromagnetic simulation. There is an optimum printing field in which the difference between ideal and calculated magnetization distributions is minimum except for checker patterns in edge printing. It was clarified that the difference in bit printing was smaller than that in edge printing. When the bit size becomes smaller, the ratio of the difference to the track pitch became larger. The difference in dot patterns was smaller than that in checker patterns for bit printing, whereas the difference in checker patterns was smaller than that in dot patterns for edge printing., The Magnetics Society of Japan
J. Magn. Soc. Jpn., 2012年05月, ［査読有り］

ECC媒体における磁気クラスタサイズの磁場印加方向依存性
山口義明,川田裕介,小峰啓史,杉田龍二, The effect of applied magnetic field direction on the magnetic cluster size of exchange coupled composite (ECC) media was analyzed by using micromagnetic simulation. The magnetization distribution in all cases exhibited a maze domain structure. The magnetic cluster size decreased as the applied field direction tilted from perpendicular to in-plane. For the hard layer only and the soft layer only, the magnetic cluster size in the perpendicular applied field was the same as that in the in-plane field. The soft layer dominated the magnetic cluster size of the ECC medium in the perpendicular field, whereas the hard layer dominated that in the in-plane field., The Magnetics Society of Japan
J. Magn. Soc. Jpn., 2012年05月, ［査読有り］

ピン止めを有するナノワイヤにおける電流誘起磁壁移動のシミュレーション
大庭 綾香; 藤村 勇馬; 小峰 啓史; 杉田 龍二,   The effect of pinning sites that originated from magnetic anisotropy distributions on critical current velocity in current-induced domain wall motion was investigated by using micromagnetic simulation. As a result, we found the pinning position and size had almost no effect on the critical current velocity. Moreover, the decrease in saturation magnetization reduced the critical current density even if the nanowire had pinning sites that originated from the anisotropy distribution. Since the estimated pinning field was attributed to the intermediate pinning region, the magnetic anisotropy distribution had almost no effect on the critical current density., 公益社団法人 日本磁気学会
J. Magn. Soc. Jpn., 2012年05月, ［査読有り］

CoPt垂直磁気異方性膜の磁気特性の膜厚依存性
川田裕介; 小野瀬勝; 川崎龍太; 大山哲広; 小峰啓史; 杉田龍二, The relation between thickness and magnetic properties of CoPt perpendicular magnetic anisotropy film was investigated through experiments and micromagnetic simulation. The perpendicular nucleation field and saturation field decreased as the film thickness decreased, whereas the in-plane squareness ratio increased as the thickness decreased. The increase in in-plane squareness ratio with decreasing thickness was due to an expansion of the domain wall region that occurred with the decrease in thickness., The Magnetics Society of Japan
J. Magn. Soc. Jpn., 2012年05月, ［査読有り］

Current-induced domain wall motion in a multilayered nanowire for achieving high density bit
T. Komine; A. Ooba; R. Sugita, We herein propose a multilayered nanowire in order to achieve a high density bit or short bit length. The multilayered nanowire consists of a continuous layer and a granular layer which are coupled by interlayer exchange and magnetostatic interactions. The continuous layer has a role of data transfer based on current-induced domain wall motion (CIDWM). The granular layer has a role of stabilizing data, and the current flows only through the continuous layer. We demonstrate CIDWM in the multilayered nanowire by micromagnetic simulation. The domain wall width in the multilayered nanowire is narrower than that of the single-layer nanowire because of weak exchange coupling in the granular layer. As a result, the smaller bit length can be obtained in the multilayered nanowire. Moreover, the critical current density in the multilayered nanowire almost equals to the critical current density of the single-layer nanowire with the same domain wall width as that of the multilayered nanowire. (C) 2012 American Institute of Physics. [doi:10.1063/1.3679760], AMER INST PHYSICS
JOURNAL OF APPLIED PHYSICS, 2012年04月, ［査読有り］

スペーシングが磁気転写特性に及ぼす影響
小野瀬勝; 川崎龍太; 小峰啓史; 杉田龍二, The effect of spacing between master and slave media on printing characteristics was investigated in this study by using micromagnetic simulation. The results indicated that the printing characteristics were improved as the spacing decreased. At the optimal printing magnetic field, the effect of the spacing for checker pattern was larger than that for L/S pattern. Decreased in the spacing expanded the tolerance region in which superior printing characteristics were obtained. Moreover, decreased in the spacing also expanded the overlap region between tolerance regions for two patterns., The Magnetics Society of Japan
J. Magn. Soc. Jpn., 2012年03月, ［査読有り］

Effect of interlayer exchange coupling on magnetization reversal process in ECC media with high coercivity
A. Oyama; T. Komine; R. Sugita, Effect of interlayer exchange coupling on time-evolutional magnetization reversal process in ECC media with high coercivity was investigated by utilizing micromagnetic simulation. In the case of intermediate value of the interlayer exchange coupling, during the application of printing field, magnetization in the soft layer initially reverses and magnetization in the hard layer follows that of the soft layer. Furthermore, after removal of printing field, magnetization in the soft layer is reversed again according with that in the hard layer., E D P SCIENCES
JEMS 2012 - JOINT EUROPEAN MAGNETIC SYMPOSIA, 2012年, ［査読有り］

Magnetic domain structure in thin CoPt perpendicular magnetic anisotropy films
Y. Kawada; M. Onose; R. Tojo; T. Komine; R. Sugita, The relation between thickness and domain structure of Co80Pt20 perpendicular magnetic anisotropy films was investigated through experiments and micromagnetic simulation. The films with thickness over 10 nm exhibited clear maze domain structure, while for the films thinner than 10 nm the domain structure abruptly changed from maze domain to irregular and large domain as the thickness became thinner. The irregular domain had narrower domain wall width than maze domain., E D P SCIENCES
JEMS 2012 - JOINT EUROPEAN MAGNETIC SYMPOSIA, 2012年, ［査読有り］

Magnetic domain structure in thin CoPt perpendicular magnetic anisotropy films
Y. Kawada; M. Onose; R. Tojo; T. Komine; R. Sugita, The relation between thickness and domain structure of Co80Pt20 perpendicular magnetic anisotropy films was investigated through experiments and micromagnetic simulation. The films with thickness over 10 nm exhibited clear maze domain structure, while for the films thinner than 10 nm the domain structure abruptly changed from maze domain to irregular and large domain as the thickness became thinner. The irregular domain had narrower domain wall width than maze domain., E D P SCIENCES
JEMS 2012 - JOINT EUROPEAN MAGNETIC SYMPOSIA, 2012年, ［査読有り］

Magnetization Distribution of Tb/in² Class Hard Disks Recorded With Bit Printing and Edge Printing　　　　　　　　　　　　　　　
T. Murakoshi; T. Komine; R. Sugita
IEEE Trans. Magn., 2011年09月, ［査読有り］

マスター媒体の初期磁化が磁気転写特性に及ぼす影響
川崎龍太,田中康貴,小峰啓史,杉田龍二, The influence of the initial magnetization of a perpendicular anisotropy master medium (PAMM) on bit printing characteristics was investigated through experiments. As a result, the initial magnetization of PAMM affected magnetic printing characteristics for a bit length of 150 nm. Here, the best magnetic printing characteristics were obtained when PAMM was initially magnetized in the direction of the printing field. However, for a bit length of 200 nm, the initial magnetization of PAMM had little influence on magnetic printing characteristics., The Magnetics Society of Japan
J. Magn. Soc. Jpn., 2011年09月, ［査読有り］

Thermoelectric propeties for single crystal bismuth nanowires using a mean free path limitation model　　　　　　　　　　　　　　　
D. Nakamura; Y. Hasegawa; M. Murata; H. Yamamoto; T. Komine
J. Appl. Phys., 2011年08月, ［査読有り］

マスター媒体のパターン形状がビット転写特性に及ぼす影響
小野瀬勝,川崎龍太,田中康貴,川田裕介,小峰啓史,杉田龍二, In this study, the bit printing characteristics of line and space (L/S), checkerboard, and dot patterns were compared in experiments. The results indicated that the peak-to-peak values of the MFM output of L/S, checkerboard, and dot patterns were almost the same. The optimum printing field for the L/S pattern was the same as that for the checkerboard pattern, whereas the optimum printing field for the dot pattern was lower than those of the L/S and checkerboard patterns. This is because the maximum value of the recording field in the dot pattern was larger than those of the L/S and checkerboard patterns., The Magnetics Society of Japan
J. Magn. Soc. Jpn., 2011年07月, ［査読有り］

低飽和磁化垂直磁気異方性細線における電流誘起磁壁移動のマイクロマグネティックシミュレーション
高橋光太,大庭綾香,小峰啓史,杉田龍二, The dependence of saturation magnetization and uniaxial anisotropy constant on current-induced domain wall motion in a magnetic nanowire with perpendicular magnetic anisotropy was analyzed through micromagnetic simulation. The results indicated that the critical current density linearly decreased by reducing the saturation magnetization. Even if the domain wall width was changed by the uniaxial anisotropy constant, the domain wall width did not influence the critical current density since the increase in the domain wall width anisotropy constant caused an increase in the effective wall anisotropy. It was revealed that the decrease in the saturation magnetization was the dominant factor in reducing the critical current density., The Magnetics Society of Japan
J. Magn. Soc. Jpn., 2011年07月, ［査読有り］

磁気転写及び磁気ヘッドで記録されたハードディスクの磁化状態
村越拓治,小峰啓史,杉田龍二, The magnetization distribution of a hard disk recorded with magnetic printing and a recording head were compared by utilizing micromagnetic simulation. The servo-signals were modeled with a line and space (L/S) pattern and a checker pattern in this study. The fidelity of recording for L/S and checker patterns were the similar for both methods. As a result, we found that the recording fidelity in magnetic printing was equal to that in head recording though both recording field strength and the gradient in magnetic printing were less than those for head recording. This is because magnetic printing has no recording demagnetization., The Magnetics Society of Japan
J. Magn. Soc. Jpn., 2011年07月, ［査読有り］

マスターパターンサイズが磁気転写特性に及ぼす影響
川前武士,小峰啓史,杉田龍二, The influence of patterned magnetic film size on edge printing characteristics was investigated using micromagnetic simulation. When the track width of the patterned magnetic film was narrower than the desired track width, the printing characteristics were improved. It was revealed that the tolerance for printing characteristics decreased as the magnetic film thickness became thinner, although the printing characteristics under the optimum printing field did not depend on magnetic film thickness., The Magnetics Society of Japan
J. Magn. Soc. Jpn., 2011年07月, ［査読有り］

Numerical Study of Effects of Scattering Processes on Transport Properties of Bi Nanowires
Yuki Ichige; Tsuyoshi Matsumoto; Takashi Komine; Ryuji Sugita; Tomosuke Aono; Masayuki Murata; Daiki Nakamura; Yasuhiro Hasegawa, In this study, we investigated the effects of scattering on the transport properties of Bi nanowires. The electrical conductivities and Seebeck coefficients of Bi nanowires were calculated using the Boltzmann equation, with an energy-dependent relaxation time corresponding to the scattering process. Decreasing the wire diameter increased the Seebeck coefficient for all of the scattering processes examined, because a semimetal-semiconductor transition occurred. In 80-nm-diameter nanowires, the Seebeck coefficient for ionized impurity scattering was larger than that of the acoustic deformation potential. On the other hand, in 20-nm-diameter nanowires, the dependence of the Seebeck coefficient on the scattering process was negligible, compared with the influence of wire diameter., SPRINGER
JOURNAL OF ELECTRONIC MATERIALS, 2011年05月, ［査読有り］

Numerical Study of Effect of Surface Potential on Transport Properties of Bi Nanowires
Tsuyoshi Matsumoto; Yuki Ichige; Takashi Komine; Ryuji Sugita; Tomosuke Aono; Masayuki Murata; Daiki Nakamura; Yasuhiro Hasegawa, We numerically investigated the effect of the surface on the transport properties of Bi nanowires. The effect of the surface was modeled using the surface potential. The energy shift in each band due to the surface potential was calculated by a perturbation method. The effect of the surface potential on the transport properties was estimated using the Boltzmann equation with a constant relaxation time. The results reveal that the surface potential dramatically alters the density of states of T-point holes, whereas it has very little effect on the density of states of L-point holes. This is because the wavefunctions at the L- and T-points have different symmetries. The electrical conductivity increases and the Seebeck coefficient decreases with increasing surface potential. The maximum absolute value of the Seebeck coefficient decreases drastically with increasing surface potential. The Seebeck coefficient has a much stronger dependence on the surface potential than on the wire diameter. These results demonstrate that the transport properties of Bi nanowires are very sensitive to the surface potential., SPRINGER
JOURNAL OF ELECTRONIC MATERIALS, 2011年05月, ［査読有り］

Numerical Analysis of Effect of Scattering Process on Transport Properties in Bi Nanowires　　　　　　　　　　　　　　　
Y. Ichige; T. Matsumoto; T. Komine; R. Sugita; T. Aono; Y. Hasegawa; M. Murata; D. Nakamura
J. Elec. Mater., 2011年05月, ［査読有り］

Crystal Orientation and Transport Properties of a 633-nm-Diameter Bismuth Nanowire
Yasuhiro Hasegawa; Daiki Nakamura; Masayuki Murata; Hiroya Yamamoto; Takashi Komine; Takashi Taguchi; Shinichiro Nakamura, The crystal orientation and resistivity of a bismuth nanowire (diameter 633 nm, length 1.91 mm) encased in quartz were measured. The nanowire surface was irradiated with a high-intensity, collimated x-ray beam through the quartz template, and several Laue spots were observed with no streak patterns. Therefore, we concluded that the nanowire was a single crystal. The crystal orientation could be determined by measuring the relationship between the Laue spot distribution and the location of the nanowire fixed by a goniometer. The direction along the wire length was strongly directed toward the bisectrix axis of bismuth. The temperature dependence of the nanowire resistivity was measured; the resistivity at 300 K was 1.40 mu Omega m, which is somewhat greater than that of the bulk sample due to the lower mobility of the nanowire. The temperature coefficient of resistivity was positive in the temperature range from 300 K to 165 K, and it became negative below 165 K. The temperature dependence can be modeled by accounting for the limited electron mean free path in the bismuth nanowire based on the crystal orientation determined by the Laue measurements., SPRINGER
JOURNAL OF ELECTRONIC MATERIALS, 2011年05月, ［査読有り］

Reduction of intrinsic critical current density for current-induced domain wall motion by using a ferrimagnetic nanowire with perpendicular magnetic anisotropy
T. Komine; K. Takahashi; A. Ooba; R. Sugita, We herein discuss the use of a ferrimagnetic nanowire for current-induced domain wall motion in order to satisfy both high perpendicular anisotropy and low saturation magnetization. We demonstrate the current-induced domain wall motion in magnetic nanowires with various saturation magnetizations by using micromagnetic and analytical calculations. The intrinsic critical current velocity was reduced with decrease of saturation magnetization even if the domain wall width was almost constant, and the intrinsic critical current velocity also can be reduced with the optimum wire width. A significant reduction of critical current density can be obtained by decreasing the saturation magnetization even if the spin polarization of ferrimagnetic materials is below 0.1 because the decrease in the hard-axis anisotropy is dominant for current-induced wall motion. (C) 2011 American Institute of Physics. [doi:10.1063/1.3545797], AMER INST PHYSICS
JOURNAL OF APPLIED PHYSICS, 2011年04月, ［査読有り］

Reduction of temperature fluctuation within low temperature region using a cryocooler
Daiki Nakamura; Yasuhiro Hasegawa; Masayuki Murata; Hiroya Yamamoto; Fumiaki Tsunemi; Takashi Komine, Modeling and experiments are performed to decrease temperature fluctuation generated by the periodic motion of the displacer in a Gifford-McMahon (GM) type cryocooler within the low-temperature region. The one-dimensional heat equation allows us to show that thermal diffusivity is an essential factor to achieve much smaller temperature fluctuation, and fiber-reinforced plastic (FRP) with low thermal diffusivity makes it possible to reduce the temperature fluctuation dramatically. Based on the model, experiments are performed to vary the thickness of two FRP dampers, on the cryohead of the cryocooler and on the sample stage. As a result, the FRP dampers enable us to achieve the temperature fluctuations of only 0.7 mK, corresponding to a standard deviation of 0.25 mK, when the sample stage is maintained at 4.2000 K, even if a GM cryocooler is utilized for cooling the temperature, which introduces an initial temperature fluctuation of 282 mK at the cryohead. (C) 2011 American Institute of Physics. [doi:10.1063/1.3581211], AMER INST PHYSICS
REVIEW OF SCIENTIFIC INSTRUMENTS, 2011年04月, ［査読有り］

垂直磁気異方性マスター媒体の磁区が転写特性に及ぼす影響
田中康貴,小峰啓史,杉田龍二, The influence of the magnetic domain of the perpendicular anisotropy master medium (PAMM) on printing characteristics is analyzed by using micromagnetic simulation. As a result, when AC-erased CoPt film makes contact with the recording layer, the magnetization of the recording layer is reversed at the position corresponding to the domain wall of the CoPt film. However, the magnetic domain has no effect on the printing characteristics in the actual printing process., The Magnetics Society of Japan
J. Magn. Soc. Jpn., 2011年03月, ［査読有り］

Numerical analysis of perpendicular magnetic printing for hard disks beyond 2 Tb/in(2)
Takuji Murakoshi; Takashi Komine; Ryuji Sugita, A micromagnetic analysis of magnetic printing onto an exchange-coupled composite (ECC) media was performed with a data signal density of over 2 Tb/in(2). Magnetic printing is a promising method of recording a servo signal onto an ECC media with data signal densities beyond 2 Tb/in(2). The printing performance was close to 100% at servo signal densities of 1.0 and 1.7 Tb/in(2). There was an optimum intergrain coupling strength in ECC media at each servo signal density, and as the servo signal density increased, the optimum intergrain coupling strength became weaker. (C) 2011 Published by Elsevier B.V. Selection and/or peer-review under responsibility of the Organising Committee of the 9th Perpendicular Magnetic Recording Conference, ELSEVIER SCIENCE BV
SPECIAL ISSUE ON THE 9TH PERPENDICULAR MAGNETIC RECORDING CONFERENCE, 2011年, ［査読有り］

Influence of domain of perpendicular anisotropy master medium on perpendicular magnetic printing
Yasuki Tanaka; Hirotaka Konishi; Takashi Komine; Ryuji Sugita, Magnetic printing is a promising way to write servo signals with high speed, high accuracy and low cost to fulfill the requirements for high-density hard disks. The PAMM (Perpendicular Anisotropy Master Medium) with CoPt magnetic layer has been proposed in order to improve the printing characteristics. However, it is worried that maze domain of the CoPt film may be printed on the hard disks. In this study, influence of the domain of the PAMM on the printing characteristics is analyzed by using micromagnetic simulation. As a result, it is clarified that the maze domain is not printed on the recording layer in the actual printing process even if the CoPt film has maze domain structure without external field. (C) 2011 Published by Elsevier B.V. Selection and/or peer-review under responsibility of the Organising Committee of the 9th Perpendicular Magnetic Recording Conference, ELSEVIER SCIENCE BV
SPECIAL ISSUE ON THE 9TH PERPENDICULAR MAGNETIC RECORDING CONFERENCE, 2011年, ［査読有り］

Thermoelectric Properties of a 593-nm Individual Bismuth Nanowire Prepared Using a Quartz Template
Daiki Nakamura; Masayuki Murata; Yasuhiro Hasegawa; Takashi Komine; Daisuke Uematsu; Shinichiro Nakamura; Takashi Taguchi, An individual bismuth nanowire sample, 593 nm in diameter and 1.64 mm in length, has been successfully grown using a quartz template. The resistivity and the Seebeck coefficient of the nanowire at 300 K were 1.35 mu Omega m and -59 mu V/K, respectively, similar to those of a bismuth bulk sample. The temperature dependence of the resistivity was found to decrease with temperature from 300 K to 175 K and then increase with further temperature reduction below 175 K. The absolute value of the Seebeck coefficient decreased with temperature from 300 K to 90 K, and the sign of the Seebeck coefficient changed from negative to positive near 90 K. This result indicated that there was a small amount of contamination in the bismuth. The carrier density was estimated from the resistivity and Seebeck coefficient on the basis of limitation of the mean free path and a two-carrier model, and the observed temperature dependences are discussed., SPRINGER
JOURNAL OF ELECTRONIC MATERIALS, 2010年09月, ［査読有り］

High-precision temperature control and stabilization using a cryocooler
Yasuhiro Hasegawa; Daiki Nakamura; Masayuki Murata; Hiroya Yamamoto; Takashi Komine, We describe a method for precisely controlling temperature using a Gifford-McMahon (GM) cryocooler that involves inserting fiber-reinforced-plastic dampers into a conventional cryosystem. Temperature fluctuations in a GM cryocooler without a large heat bath or a stainless-steel damper at 4.2 K are typically of the order of 200 mK. It is particularly difficult to control the temperature of a GM cryocooler at low temperatures. The fiber-reinforced-plastic dampers enabled us to dramatically reduce temperature fluctuations at low temperatures. A standard deviation of the temperature fluctuations of 0.21 mK could be achieved when the temperature was controlled at 4.200 0 K using a feedback temperature control system with two heaters. Adding the dampers increased the minimum achievable temperature from 3.2 to 3.3 K. Precise temperature control between 4.200 0 and 300.000 K was attained using the GM cryocooler, and the standard deviation of the temperature fluctuations was less than 1.2 mK even at 300 K. This technique makes it possible to control and stabilize the temperature using a GM cryocooler. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3484192], AMER INST PHYSICS
REVIEW OF SCIENTIFIC INSTRUMENTS, 2010年09月, ［査読有り］

Electrical nanocontact between bismuth nanowire edges and electrodes　　　　　　　　　　　　　　　
M. Murata; D. Nakamura; Y. Hasegawa; T. Komine; D. Uematsu; S. Nakamura; T. Taguchi
J. Elec. Mater., 2010年06月, ［査読有り］

Numerical analysis of effective thermal conductivity in microwire array element　　　　　　　　　　　　　　　
T. Komine; M. Kuraishi; T. Teramoto; R. Sugita; Y. Hasegawa; M. Murata; D. Nakamura
J. Elec. Mater., 2010年05月, ［査読有り］

Influence of exchange coupling on current-driven domain wall motion in a nanowire　　　　　　　　　　　　　　　
T. Komine; K. Takahashi; H. Murakami; R. Sugita
J. Magn. Magn. Mater., 2010年05月, ［査読有り］

CoPt 垂直マスターの転写特性における組成依存性
小西弘孝,川崎龍太,田中康貴,小峰啓史,杉田龍二, 本研究では,CoPt垂直磁気異方性マスター(PAMM)におけるPt含有量が転写特性に及ぼす影響を,実験及びシミュレーションにより検討した.その結果,Pt含有量が10〜20%のときに最も優れた転写特性が得られた.この結果は異方性と飽和磁化により説明することができる.また,PAMMの最適転写磁場は,pure Coマスターの最適転写磁場に比べ約1.0kOe低くなった., 一般社団法人 映像情報メディア学会
電子情報通信学会技術研究報告, 2010年05月, ［査読有り］

マスターパターン形状が磁気転写特性に及ぼす影響
田辺和博,齊藤俊明,ヌルシダ,小峰啓史,杉田龍二, A master pattern with the a line-and-space (L/S) part and a checker part in the servo signals was made by using an FeCo film, and the edge printing characteristics of both parts were compared. The MFM output in the checker part was equal to the L/S part for a bit length of 200 nm, while for a bit length of 100 nm, the MFM output in the checker part decreased by about 30% compared with that in the L/S part, because of the MFM's low resolution. However, for a bit length of 100 nm, simulation results showed that the edge-printed magnetization of the checker part was equal to that of the L/S part. When the TMR head reproduced both parts, the output in the checker part was equal to that in the L/S part. The optimum printing field for the checker part was the same as that for the L/S part. Moreover, the rate of decrease in the MFM output did not depend on the printing field., The Magnetics Society of Japan
J. Magn. Soc. Jpn., 2010年05月, ［査読有り］

垂直磁気異方性ナノワイヤにおけるmulti-wall の磁壁移動
村上宏,高橋光太,小峰啓史,杉田龍二, The current-driven domain motion of a multi-wall in a magnetic nanowire with perpendicular magnetic anisotropy was analyzed in this study by using micromagnetic simulation. As a result, we found that there were two modes in the multi-wall motion, and the motion was determined by the applied current density and non-adiabatic spin torque parameters; this was similar to single-wall motion. The x-component of magnetization in the domain wall exhibited different behavior according to the current density. The bit length was extended for a low current density and the bit length was varied for a high current density due to interaction between the magnetic domain walls., The Magnetics Society of Japan
J. Magn. Soc. Jpn., 2010年05月, ［査読有り］

磁性細線における電流誘起磁壁移動の交換スティフネス定数依存性
高橋光太,村上宏,小峰啓史,杉田龍二, The dependence of the exchange stiffness constant on current-driven domain wall motion in a magnetic nanowire was examined through micromagnetic simulation. As a result, we found that the critical current density changes according to the width of the domain wall at the edge of the nanowire., The Magnetics Society of Japan
J. Magn. Soc. Jpn., 2010年05月, ［査読有り］

ECC媒体への垂直磁気転写シミュレーション
村越拓治,小峰啓史,杉田龍二, 本研究では,マイクロマグネティックシミュレーションを用いて,ECC媒体への垂直磁気転写特性について調べた.ECC媒体の層間交換結合が強く,硬磁性層と軟磁性(半硬磁性)層の磁化が一緒に反転する領域では,単層媒体と同等程度の転写特性をもつことがわかった.熱安定性を等しくした場合,ECC媒体は,単層媒体に比べ最適転写磁場が低くなり,書き込み易さが向上していることがわかった.また,ECC媒体ではSemi-ECC媒体に比べ,層間の交換結合をより強くする必要があることがわかった., 一般社団法人 映像情報メディア学会
J. Magn. Soc. Jpn., 2010年05月, ［査読有り］

パターンの異なるマスターによる垂直磁気転写
田中康貴,小西弘孝,小峰啓史,杉田龍二, Magnetic printing characteristics using a perpendicular anisotropic master medium (PAMM) with various patterns were numerically analyzed. The recording field distribution of PAMM and the magnetization distribution of the recording layer were analyzed by micromagnetic simulation. As a result, the recording field of dot a pattern was about 1 kOe higher than those of line and checker patterns under the same printing field. The magnetic printing with PAMM was found to be applicable to any pattern. When the bit length was not more than 100 nm, the optimum printing field for the dot pattern was 1-2 kOe lower than those of line and checker patterns. The optimum printing field varied according to pattern and bit length., The Magnetics Society of Japan
J. Magn. Soc. Jpn., 2010年03月, ［査読有り］

垂直磁気転写法によるサーボ信号記録(記録システムおよび一般)
杉田 龍二; 小峰 啓史, 磁気転写法を用いることにより,ハードディスクにサーボ信号を,従来方法に比べて桁違いの高速,高精度,かつ低コストで書き込むことができる.垂直ハードディスクに磁気転写する方法としては,転写時にディスク面に垂直に転写磁場を印加するビット転写と,ディスク面に平行に印加するエッジ転写がある.前者によって転写されたディスクからの再生波形は,磁気ヘッド記録されたディスクからの再生波形に近いという利点がある.一方,後者は短ビット長領域において高いS/Nが期待できる.垂直磁気転写は,50nm以下のビット長に対しても可能であり,Tb/in^2級ハードディスクに対応できる性能を有している., 一般社団法人 映像情報メディア学会
映像情報メディア学会技術報告, 2010年

Micromagnetic study of magnetic printing onto various slave media
Takashi Komine; Takuji Murakoshi; Yasuki Tanaka; Yuichi Sakaguchi; Ryuji Sugita, In this paper, the micromagnetic analysis of magnetic printing onto various slave media, such as the coupled granular-continuous media (CGC) and exchange coupled composite media (ECC) was carried out. In the single-layered granular medium, the magnetization patterns are printed on the slave medium corresponding to the master patterns, but defects appear in the center of the magnetization pattern in this case. On the other hand, in the CGC and ECC media, there is no defect in the center of the magnetization patterns due to the effect of a capping layer. The bit squareness in ECC medium is superior to those of the other media. It is clarified that the magnetic printing can be applied onto various media., IOP PUBLISHING LTD
INTERNATIONAL CONFERENCE ON MAGNETISM (ICM 2009), 2010年, ［査読有り］

Micromagnetic analysis of current-driven domain wall motion of multi-bit in a nanowire with perpendicular magnetic anisotropy
Hiroshi Murakami; Kouta Takahashi; Takashi Komine; Ryuji Sugita, The current-driven domain wall motion of a multi-bit in a magnetic nanowire with perpendicular magnetic anisotropy has been analyzed by performing a micromagnetic simulation. The multi-bit motion is determined by the applied current density and the non-adiabatic spin torque parameters, which is similar to the current-driven domain wall motion of the single wall. Consequently, it was found that are two modes in the multi-bit motion: (a) the bit length remains constant and (b) the bit length varies or the bit vanishes in the nanowire. It was found that these modes of the multi-bit motion can be classified by the critical current density or Walker breakdown for the single wall motion in a magnetic nanowire with perpendicular magnetic anisotropy., IOP PUBLISHING LTD
INTERNATIONAL CONFERENCE ON MAGNETISM (ICM 2009), 2010年, ［査読有り］

Effect of Non-adiabatic Spin Torque Parameter on Domain Wall Motion Driven by Pulse Current in a Magnetic Nanowire　　　　　　　　　　　　　　　
H. Murakami; T. Komine; R. Sugita
IEEE Trans. Magn., 2009年09月, ［査読有り］

Perpendicular anisotropy master medium in magnetic printing for writing high density servo signal
Nurul Sheeda; M. Nakazawa; H. Konishi; T. Komine; R. Sugita
IEEE Trans. Magn., 2009年09月, ［査読有り］

Reducing thermal conductivity of thermoelectric materials by using a narrow wire geometry
Yasuhiro Hasegawa; Masayuki Murata; Daiki Nakamura; Takashi Komine, The dependence of the thermal conductivity of narrow wires made from bismuth and covalently bonded materials on wire diameter was numerically calculated by considering contributions of mean free paths of carriers and phonons. The results suggest that a reduction in the thermal conductivity should be observable in a bismuth wire having a diameter of less than 1 mu m sample. A reduction of nearly 20% in the temperature range of 150-300 K is expected due to the use of a narrow wire geometry. Such a geometry reduces the mobility and the thermal conductivity of the carriers, which is the dominant component, while the thermal conductivity due to phonons was dramatically reduced by using narrow wires at temperatures under 50 K due to the longer mean free path phonons. The thermal conductivity of materials with covalent bonding such as silicon was also estimated, and it is expected that the thermal conductivity of a silicon wire could be reduced due to the mean free path of phonons being longer than that of the carriers. The results suggest that it should be possible to enhance the figure of merit by reducing the thermal conductivity through using wire geometries having diameters of less than 100 nm in materials having low mobilities, high thermal conductivities, and high Debye temperatures. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3212982], AMER INST PHYSICS
JOURNAL OF APPLIED PHYSICS, 2009年09月, ［査読有り］

Thermoelectric Properties of Bismuth Micro/Nanowire Array Elements Pressured into a Quartz Template Mold
Yasuhiro Hasegawa; Masayuki Murata; Daiki Nakamura; Takashi Komine; Takashi Taguchi; Shinichiro Nakamura, A quartz template having a length of several millimeters and with holes having diameters on the order of micro/nanometers was fabricated. Bismuth was injected into the template holes by high-pressure injection. A bismuth micro/nanowire array sample was prepared, and the temperature dependence of the Seebeck coefficient and the resistance were measured in the temperature range of 50 K to 300 K. Although the temperature dependence of the Seebeck coefficient is similar to that of polycrystalline bulk bismuth, the temperature coefficient of the resistance is much less than that of the bulk sample. The magnetic-field dependence of the Seebeck coefficient was also measured. The Umkehr effect was observed, demonstrating that the mixed micro/nanowires are a bundle of single-crystal wires. The magnitude of the absolute value of the Seebeck coefficient was found to be large in high magnetic field and at low temperature., SPRINGER
JOURNAL OF ELECTRONIC MATERIALS, 2009年07月, ［査読有り］

Mean free path limitation of thermoelectric properties of bismuth nanowire
Masayuki Murata; Daiki Nakamura; Yasuhiro Hasegawa; Takashi Komine; Takashi Taguchi; Shinichiro Nakamura; Christopher M. Jaworski; Vladimir Jovovic; Joseph P. Heremans, A limiting mean free path was considered in order to better understand the temperature and wire diameter dependence of the resistivity and Seebeck coefficient of bismuth microwire and nanowire samples. The mean free path limited mobility was numerically calculated from experimentally measured mobility in a bulk bismuth sample, and the electron and hole mobilities were dramatically decreased to a 10 mu m mean free path. Therefore, the temperature dependence of resistivity in very thin wire was quite different from that of a bulk sample, which had a positive temperature coefficient. The calculations showed that the temperature coefficient decreased gradually with decreasing mean free path, and the coefficient became negative for a mean free path of less than 1 mu m at about 150 K. The Seebeck coefficient was also calculated, but showed only a weak dependence on mean free path compared with the resistivity. Experimental comparisons were made to previous measurements of bismuth microwire or nanowire samples, and the temperature and wire diameter dependencies of the resistivity and Seebeck coefficient were qualitatively and quantitatively in very good agreement. Therefore, the temperature dependencies of nanowire samples over 850 nm in diameter were well described using the mean free path limitation. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3131842], AMER INST PHYSICS
JOURNAL OF APPLIED PHYSICS, 2009年06月, ［査読有り］

磁性細線における磁壁移動の電流パルス波形依存性
村上宏・小峰啓史・杉田龍二, 本研究では,切り込みのある磁性細線における磁壁電流駆動に及ぼす電流パルス波形の影響についてマイクロマグネティックシミュレーションを用いて調べた.その結果,適切なパルス周波数を持つ電流によって,磁壁デピニングが促進されること,最適パルス周波数は切り込みのピン止めポテンシャルに起因する磁壁の固有周波数よりもわずかに低い周波数であることが明らかとなった.磁性細線の両端に切り込みがある場合,磁壁に対するピン止め効果が異なるため,磁壁の固有振動数が変化し,磁壁の連成振動が起こっていることがわかった.電流パルスのdutyを変えたところ,dutyが0.5のときに磁壁デピニングが促進されることが分かった., 一般社団法人 映像情報メディア学会
J. Magn. Soc. Jpn., 2009年05月, ［査読有り］

磁気転写及びヘッド記録された媒体からの出力波形
田辺和博・岡見智史・齋藤俊明・小峰啓史・杉田龍二, First, the relation between MFM output and head output waveforms from perpendicular magnetic printed media was clarified. Next, the MFM output waveforms from magnetically printed and head-recorded media were compared by using metal-evaporated (ME) tape as a slave medium. The MFM output waveform corresponds very closely with the head output waveform, and it appears that the MFM output is similar to the perpendicular component of the stray field. In the case of a long bit length, the bit-printing (BP) waveform is similar to the head-recording (HR) waveform, while the edge-printing (EP) waveform is significantly different from the HR waveform. On the other hand, in the case of a short bit length, the BP, EP, and HR waveforms are all sinusoidal, but the phase of the EP waveform is 90° shifted from the HR waveform, while the BP waveform is almost identical to the HR waveform., The Magnetics Society of Japan
J. Magn. Soc. Jpn., 2009年05月, ［査読有り］

Analysis of Waveform from Magnetic Printed Perpendicular Hard DisAnalysis Disk　　　　　　　　　　　　　　　
N. Sheeda; S. Okami; Y. Sakaguchi; T. Komine; R. Sugita
J. Magn. Soc. Jpn., 2009年05月, ［査読有り］

Thermoelectric properties of bismuth nanowires in a quartz template
Masayuki Murata; Daiki Nakamura; Yasuhiro Hasegawa; Takashi Komine; Takashi Taguchi; Shinichiro Nakamura; Vladimir Jovovic; Joseph P. Heremans, Bismuth nanowires with lengths of over 1 mm length and diameters of the order of nanometers have been fabricated by high-pressure injection into a quartz template. The temperature dependences of the Seebeck coefficient and resistivity were simultaneously measured over the temperature range of 77-300 K. The Seebeck coefficient and resistivity at 300 K were estimated to be approximately -57 mu V/K and 1.31 mu Omega m, respectively. We also estimated the mobilities of electrons and holes to determine their temperature dependences. We found that the temperature dependence of the resistivity can be accounted for by the reduction in the mobility., AMER INST PHYSICS
APPLIED PHYSICS LETTERS, 2009年05月, ［査読有り］

Mobility estimation in microsized bismuth wire arrays
Yasuhiro Hasegawa; Masayuki Murata; Daiki Nakamura; Takashi Komine; Takashi Taguchi; Shinichiro Nakamura, Wire-diameter dependencies were investigated using microwire sample arrays with diameters from 2 to 25 mu m and polycrystalline bulk bismuth. Seebeck coefficient and resistivity were measured from 50 to 300 K. Although the temperature dependence of the Seebeck coefficients of all samples were similar to that of the bulk, the resistivity dependence of the 2-mu m-diameter microwire array sample had a small positive temperature coefficient, and was quite different from the other samples. Mobility was estimated using a simple model to identify the dependences on temperature and wire diameter. The ratio of electron mobility divided by hole mobility gradually decreased with decreasing temperature for samples with wire diameters below 6 mu m, and electron mobility was suppressed at low temperatures, explaining the promotion of the boundary scattering. Therefore, small positive temperature coefficients of resistivity were obtained for very small diameter microwire array samples. To compare with the temperature dependence of the nanowire array samples that typically have negative temperature coefficient reported, a model for mobility was developed to represent the temperature dependence of resistivity., AMER INST PHYSICS
JOURNAL OF APPLIED PHYSICS, 2009年05月, ［査読有り］

垂直異方性マスター媒体を用いた磁気転写の数値解析
中澤光貴, 小西弘孝,Nurul Sheeda; 小峰啓史,杉田龍二, A perpendicular anisotropy master medium (PAMM) is proposed. The PAMM is composed of CoPt film with perpendicular magnetic anisotropy and large saturation magnetization. The magnetization distributions of PAMM and conventional master media (using an FeCo soft magnetic layer) were analyzed by using micromagnetic simulation. It was found that the peak-to-valley value of the recording field and the recording field gradient at the edge of the patterned magnetic film of PAMM were larger than those of the conventional master medium. Furthermore, the peak-to-valley value of the recording field and the recording field gradient of PAMM did not depend on the strength of the printing field. The printing characteristic of PAMM is twice that of the conventional master medium. Furthermore, the optimum printing field for PAMM is 1 kOe lower than that of the conventional master medium. As a result, PAMM is expected to improve the printing characteristic of the bit printing method., 公益社団法人日本磁気学会
J. Magn. Soc. Jpn., 2009年03月, ［査読有り］

マスターパターンの傾きが垂直磁気転写特性に及ぼす影響
齋藤俊明,坂口雄一,岡見智史,小峰啓史,杉田龍二, The influence of the inclination angle of the master pattern on the edge printing characteristics for writing phase servo patterns on perpendicular magnetic recording media was investigated. Even if the master pattern angle is 40 degrees, the printing characteristics are only 10 percent lower than when the angle is 0 degrees. The influence of the inclination angle of the master pattern on the printing characteristics is also small when the bit length is changed. The contribution of the in-plane component of the recording field to magnetization reversal is large in edge printing. Although the perpendicular component of the recording field decreases markedly as the inclination angle of the master pattern increases, edge printing can be used for writing phase servo patterns on slave media., 公益社団法人日本磁気学会
J. Magn. Soc. Jpn., 2009年03月, ［査読有り］

Influence of Notch Shape and Size on Current-Driven Domain Wall Motions in a Magnetic Nanowire
T. Komine; H. Murakami; T. Nagayama; R. Sugita, 電流駆動ナノワイヤ磁壁メモリにおける切り込みが磁壁移動に及ぼす影響を解析した．また，電流分布を考慮した磁壁移動解析の方法を提案した．その結果，切り込み部に集中する電流分布によって様々な磁壁移動モードが表れることを明らかにした．, 一般社団法人 映像情報メディア学会
IEEE Trans. Magn., 2008年12月, ［査読有り］

Feasibility of Perpendicular Magnetic Duplication at 1 Tbit/inch²　　　　　　　　　　　　　　　
T. Komine; T. Murata; Y. Sakaguchi; Y. Hosoya; N. Sheeda Suhaimi; R. Sugita, 超高記録密度ビット転写の可能性を解析したところ，1Tbit/inch²の超高密度でも十分な潜在能力を有していることを明らかにした．
IEEE Trans. Magn., 2008年12月, ［査読有り］

Feasibility of Perpendicular Magnetic Printing at 1 Tb/in(2)
Takashi Komine; Takeshi Murata; Yuichi Sakaguchi; Ryuji Sugita, The feasibility of perpendicular magnetic printing for ultrahigh-density hard disks (HDs) was investigated by using the micromagnetic simulation. Our results suggest that the exchange constant dependence of the printing performance has a maximum value and the applied printing field should be less than the coercivity. Although the printing performance slightly deteriorates as the recording density increases, the printing performance is expected to be kept 70% at 1 Tb/in(2). Therefore, it was clarified that the perpendicular magnetic printing is feasible even at ultrahigh density such as 1 Tb/in(2)., IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
IEEE TRANSACTIONS ON MAGNETICS, 2008年11月, ［査読有り］

Analysis of waveform from perpendicular magnetic printed media
Nurul Sheeda; Satoshi Okami; Takashi Komine; Ryuji Sugita
J. Magn. Magn. Mater., 2008年10月, ［査読有り］

Influence of the band structure of BiSb alloy on the magneto-Seebeck coefficient
Takayuki Teramoto; Takashi Komine; Shinji Yamamoto; Masahiro Kuraishi; Ryuji Sugita; Yasuhiro Hasegawa; Hiroaki Nakamura, The influence of the band structure of BiSb alloys on the magneto-Seebeck coefficient was estimated by the Boltzmann equation using an energy-dependent relaxation time approximation at 100 K. The magneto-Seebeck coefficient along the trigonal direction was calculated under a magnetic field along the bisectrix direction. The scattering factor was supposed as being an acoustic deformation potential scattering. In order to estimate the influence of band structure on the magneto-Seebeck coefficient, both two band and three band models were utilized. The two band model consists of an electron surface at the L-point and a hole surface at the T-point. The influence of the change in band overlap and the effective electron mass was investigated using the two band model. The three band model consists of an electron surface at the L-point and a hole surface at the T-point. The influence of change in the Sb concentration of BiSb alloy was also investigated using the three band model. As a result, the Seebeck coefficient was observed to increase as the band overlap decreased. The band overlap has little influence on the improvement of the magneto-Seebeck coefficient. The Seebeck coefficient decreases as the effective mass decreases; however, improvement in the magneto-Seebeck coefficient increases as the effective mass decreases. The magneto-Seebeck coefficient of Bi(95)Sb(5) was effectively improved under a low maonetic field. (C) 2008 American Institute of Physics., AMER INST PHYSICS
JOURNAL OF APPLIED PHYSICS, 2008年09月, ［査読有り］

垂直磁気転写におけるマスター磁性膜及び軟磁性裏打層のマイクロマグネティックシミュレーション　　　　　　　　　　　　　　　
中澤光貴,小峰啓史,杉田龍二
J. Magn. Soc. Jpn., 2008年07月, ［査読有り］

1 Tbit/inch² 垂直磁気転写の可能性　　　　　　　　　　　　　　　
村田剛史,坂口雄一,和泉昭彦,小峰啓史,杉田龍二, 1 Tbit/inch²の超高密度媒体に対する磁気転写の可能性をマイクロマグネティックシミュレーションにより検討して，磁気転写に十分な潜在能力があることを明らかにした．日本磁気学会学術奨励賞(内山賞),08/09/14
J. Magn. Soc. Jpn., 2008年05月, ［査読有り］

垂直磁気転写特性のマスターパターン傾斜角依存性の拡大モデルによる解析　　　　　　　　　　　　　　　
齋藤俊明,安田浩子,小峰啓史,杉田龍二
J. Magn. Soc. Jpn., 2008年05月, ［査読有り］

スレーブ媒体の磁気特性が垂直磁気転写特性に及ぼす影響　　　　　　　　　　　　　　　
坂口雄一,村田剛史,小峰啓史,杉田龍二
J. Magn. Soc. Jpn., 2008年05月, ［査読有り］

非一様電流による磁壁駆動のマイクロマグネティックシミュレーション　　　　　　　　　　　　　　　
小峰啓史,村上宏,永山剛広,杉田龍二, 強磁性ナノワイヤにおける電流駆動磁壁移動において，ナノワイヤ端部の切り込みなどにより生じる電流分布を考慮したマイクロマグネティックシミュレーションを提案し，切り込みが閾値電流等に及ぼす影響を議論した．日本磁気学会学術奨励賞(内山賞),08/09/14
J. Magn. Soc. Jpn., 2008年05月, ［査読有り］

Numerical analysis of the magneto-Seebeck effect of bismuth with anisotropic band structure
Takayuki Teramoto; Takashi Komine; Masahiro Kuraishi; Ryuji Sugita; Yasuhiro Hasegawa; Hiroaki Nakamura, We studied the influence of band structure on the Seebeck coefficient of bismuth under a magnetic field. In this study, the magneto-Seebeck coefficient was calculated by solving the Boltzmann equation with an energy-dependent relaxation-time approximation and by assuming the Lax model of the bismuth band structure, which contains the anisotropy of bismuth. The influence of the scattering factor on the magneto-Seebeck effect was also investigated in the anisotropic band structure. The magneto-Seebeck coefficient varies with the magnetic field direction. Improvement of the Seebeck coefficient under a transverse magnetic field is higher than that under a longitudinal magnetic field. For the acoustic deformation potential scattering, the Seebeck coefficient is improved in a low magnetic field. For other types of scattering, the absolute values of the Seebeck coefficient are decreased in the low magnetic field. Moreover, for scattering factor r of 0, the magneto-Seebeck coefficient for a parabolic band does not vary, while the magneto-Seebeck coefficient for a nonparabolic band decreases. The sign of the Seebeck coefficient was changed under a high magnetic field because of the increase in magnetoresistivity due to high electron mobility. The effect of impurity addition was also investigated by changing the Fermi energy. With increasing Fermi energy, the Seebeck coefficient is more easily affected by an applied magnetic field, because the electron density is increased., AMER INST PHYSICS
JOURNAL OF APPLIED PHYSICS, 2008年02月, ［査読有り］

Power factor enhancement in a magnetic field using polycrystalline bismuth microwire arrays
Yasuhiro Hasegawa; Hirofumi Nakano; Hiroyuki Morita; Takashi Komine; Haruhiko Okumura; Hiroaki Nakamura, Measurements of the magneto-Seebeck coefficient and magnetoresistivity of two bismuth microwire arrays having different diameters and a bulk sample were performed for applied magnetic fields between 0 and 2 T and temperatures between 50 and 300 K. The magneto-Seebeck coefficients were always enhanced as a result of controlling the phonon scattering process and the magnetoresistivity also invariably increased. The power factors in an applied magnetic field were estimated, and the power factors of the microwire arrays were found to be enhanced over the whole measurement range. By contrast, the power factor of the bulk sample was not enhanced at temperatures under 200 K. The difference in the responses of the bulk sample and the microwire arrays is strongly related to suppression of the magnetoresistivity; the suppression ratios of the magnetoresistivity of the bulk sample, which has a low aspect ratio, are smaller than those of the microwire arrays. It was experimentally demonstrated that there is an optimum magnetic field that maximizes the power factor and that the enhancement ratio of the power factor is much greater for structures that have a high aspect ratio, such as microwire arrays. This suggests that microwire arrays are suitable for enhancing the power factor by applying a magnetic field. (C) 2007 American Institute of Physics., AMER INST PHYSICS
JOURNAL OF APPLIED PHYSICS, 2007年10月, ［査読有り］

拡大モデルを用いた垂直磁気転写解析
安田浩子,永利賢,鈴木麻希子,小峰啓史,杉田龍二, Experiments on perpendicular magnetic contact duplication by using enlarged models were conducted, where we investigated what influence the strength of the duplication field and the magnetic layer thickness of the master had on duplication characteristics. Excellent duplication characteristics were obtained with bit printing when the duplication field was around the value of the coercivity of the slave, and the duplication characteristics improved as the magnetic layer of the master became thicker. In edge printing, the duplication characteristics improved as the duplication field was increased up to a certain field strength, above which the characteristics saturated, and barely depended on the thickness of the magnetic layer in the master. When their duplication magnetizations were compared, edge printing was more advantageous than bit printing., The Magnetics Society of Japan
日本応用磁気学会誌, 2007年09月, ［査読有り］

垂直磁気転写特性に及ぼす軟磁性裏打ち層の影響
和泉昭彦,小峰啓史,村田剛史,杉田龍二, The magnetic field distributions around slave media with and without SUL were calculated by using the finite element method to estimate what influence a soft-under-layer (SUL) in a double-layered perpendicular medium had on magnetic duplication characteristics. As a result, we found the SUL enhanced duplication characteristics for any bit length and track width. The SUL in bit printing influences the duplication characteristics more than that in edge printing. The influence of SUL on duplication characteristics in bit printing increases as the strength of the duplication field increases. However, in edge printing, there is a duplication field that maximizes the influence of SUL on duplication characteristics. Moreover, the influence of SUL on duplication characteristics decreases with both bit and edge printing as bit the length of the magnetic pattern decreases, and also decreases as the track width decreases. These dependencies can be explained by taking the demagnetization coefficient of SUL and the total amount of magnetic charge appearing in SUL and magnetic patterns into account., The Magnetics Society of Japan
日本応用磁気学会誌, 2007年09月, ［査読有り］

Influence of spacing between master and slave media on magnetic duplication characteristics for perpendicular recording media
Takeshi Murata; Akihiko Izumi; Satoshi Okami; Nurul Sheeda Binti Suhaimi; Takashi Komine; Ryuji Sugita, There are two methods of writing servo signals with high speed in a perpendicular magnetic recording medium by magnetic duplication: bit printing (BP) and edge printing (EP). In this study, the influence of spacing between master and slave media on duplication characteristics in both BP and EP has been investigated by the three-dimensional finite-element method. The results show that the duplication characteristic in each method is deteriorated with a large spacing. Also, the influence of a small spacing is stronger in BP than in EP., IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG
IEICE TRANSACTIONS ON ELECTRONICS, 2007年08月, ［査読有り］

蒸着テープを用いた垂直磁気転写解析
岡見智史,丑米梨恵,Nurul Sheeda,小峰啓史,杉田龍二
日本応用磁気学会誌, 2007年05月, ［査読有り］

垂直磁気転写された媒体磁化のマイクロマグネティックシミュレーション
小峰啓史,和泉昭彦,村田剛史,杉田龍二, 磁気転写された垂直磁化膜の磁化状態をマイクロマグネティックシミュレーションにより解析した．ビット転写及びエッジ転写における磁化状態の転写条件依存性及びスレーブ媒体の磁気特性との関係について議論した．, The Magnetics Society of Japan
日本応用磁気学会誌, 2007年05月, ［査読有り］

マスター媒体の飽和磁化が垂直磁気転写特性に及ぼす影響
村田剛史,和泉昭彦,小峰啓史,杉田龍二, The influence of saturation magnetization of a master disk on its perpendicular magnetic contact duplication characteristics was investigated by using the two-dimensional finite element method. An investigation of bit printing (where the duplication field is applied in a direction perpendicular to the disk plane) and edge printing (where the duplication field is applied in an in-plane direction), revealed the following points. In bit printing, the influence of saturation magnetization of a master disk on perpendicular duplication characteristics is very small when the duplication field is nearly equal to the coercivity of the slave (4 kOe), which is the optimum field. On the other hand, in edge printing, the duplication characteristics are better for high saturation magnetization of a master disk than for low saturation magnetization. The cause of this difference in the influence of saturation magnetization of a master disk is the demagnetizing field of the master. In bit printing, the influence of saturation magnetization of a master disk is small because of the high demagnetizing field coefficient, while in edge printing, the influence of saturation magnetization of a master disk is large because of the low demagnetizing field coefficient., The Magnetics Society of Japan
日本応用磁気学会誌, 2007年03月, ［査読有り］

Aspect ratio dependence of magnetoresistivity in polycrystalline bismuth microwire arrays
Yasuhiro Hasegawa; Hirofumi Nakano; Hiroyuki Morita; Akio Kurokouchi; Kentarou Wada; Takashi Komine; Hiroaki Nakamura, Magnetoresistivity measurements of polycrystalline bismuth microwire arrays having a range of different diameters and a bulk sample were performed under applied magnetic fields between 0 and 2 T and temperatures from 50 to 300 K. A thin film layer was deposited on the terminations of the microwire arrays in order to completely eliminate contact resistance. The measured resistivities were in very good agreement with those of polycrystalline bulk bismuth over the entire measured temperature range, even when the resistances had different values. The magnetoresistivities increased when a magnetic field was applied, and the rate of increase of the magnetoresistivities with applied magnetic field varied in samples having different aspect ratios. It was conjectured that this variation in the rate of increase is related to the aspect ratio. Suppression of magnetoresistivity in the microwire arrays was confirmed experimentally using bulk bismuth since the aspect ratio of the microwire arrays was much larger than that of the bulk sample. The geometrical contribution of the high aspect ratio on the magnetic effect in microwire and nanowire arrays makes it possible to enhance the thermoelectric performance of materials by suppressing the magnetoresistivity and increasing the magneto-Seebeck coefficient. (c) 2007 American Institute of Physics., AMER INST PHYSICS
JOURNAL OF APPLIED PHYSICS, 2007年02月, ［査読有り］

Potential of servo pattern printing on PMR media with high-density servo signal pattern
M. Nishikawa; S. Wakamatsu; K. Ichikawa; T. Usa; M. Nagao; T. Ishioka; T. Yasunaga; T. Komine; R. Sugita, Servo pattern printing (SPP) is recognized as a candidate for the future high resolution and high throughput servo track writing method. In terms of the application to perpendicular magnetic recording (PMR) media, there are two methods of SPP, "edge printing (EP)" and "bit printing (BP)," which use horizontal and vertical external field during printing process, respectively. Comparing between EP and BP, EP has higher potential for the PMR application, because of the properties of a de-free signal, a higher signal-to-noise ratio (SNR) and smaller repeatable run out (RRO) from 8th to 19th order than a conventional head writing method. In the simulation, the less write-fringe of the recorded bits was confirmed as the benefits of EP. The most recent experiment demonstrated 55-nm bit length (BL) with adequate read back signal and EP is considered to have adaptability to the areal density beyond 48 Gbits/cm(2) (300 Gbpsi)., IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
IEEE TRANSACTIONS ON MAGNETICS, 2006年10月, ［査読有り］

スレーブ媒体磁化困難軸方向に対するマスターパターンの傾きが,磁気転写特性に及ぼす影響
安田浩子,金子朝子,小峰啓史,杉田龍二,村野井徹夫, Magnetic contact duplication is proposed as a method for forming phase servo patterns on hard disks. In a phase servo pattern, the magnetic field used for duplication is applied diagonally across the master pattern. This work clarifies the influence of the master pattern angle θ against hard magnetization direction of the slave medium on the magnetic duplication characteristics. In the case where θ= 30°, the output signal voltage decreases and the half-value width of the signal becomes broad compared with that for θ= 0°; that is, the magnetic duplication characteristics deteriorate as θ increases. Even if the duplication field is made strong for large θ, the magnetic duplication characteristics are not improved., The Magnetics Society of Japan
日本応用磁気学会誌, 2006年05月, ［査読有り］

垂直磁気記録媒体への磁気転写シミュレーション
和泉昭彦,長濱幸雄,小峰啓史,杉田龍二,村野井徹夫, The characteristics of magnetic contact duplication for perpendicular magnetic recording media are investigated by using the three-dimensional finite element method. In order to magnetically duplicate a servo signal on perpendicular recording media, there are two methods of applying a duplication magnetic field. One is method to apply a magnetic field in a direction perpendicular to the disk plane (perpendicular field application, PFA), and the other is to apply a field in the disk plane (in-plane field application, IFA). In PFA, the dependence of the duplication performance on the field strength has an optimum value which is around the coercivity of the slave medium. In IFA, the duplication performance is improved by increasing the duplication field up to a certain field strength beyond which the strength the performance is saturated. Duplication characteristics of the slave media change a little even though the track width decreases in the case of PFA, while it decreases with decreasing track width in the case of IFA. The results of simulation show that IFA is more advantageous than PFA for duplication of perpendicular magnetic recording media., The Magnetics Society of Japan
日本応用磁気学会誌, 2006年03月, ［査読有り］

磁気転写及び磁気ヘッドで記録された媒体磁化の数値解析
太田篤志,小峰啓史,杉田龍二,村野井徹夫, The magnetization distributions of recording layers recorded by magnetic head writing and magnetic duplication were calculated by the two-dimensional finite element method. The recording characteristics of the two methods were evaluated by comparing the magnetization distributions. In head recording, conspicuous bit shifts appeared when the recording current was optimal. In magnetic duplication, slight bit shifts were obtained when the strength of the applied field was greater than optimal. The reproduced output signals were calculated from the magnetization distributions of recording layers recorded by magnetic head writing and magnetic duplication. As a result, it was found that the output voltages of magnetic duplication were the same as those of head recording., The Magnetics Society of Japan
日本応用磁気学会誌, 2006年03月, ［査読有り］

磁気転写用磁石の斜め方向磁場が転写特性に及ぼす影響
富川智史,稲葉望,小峰啓史,杉田龍二,村野井徹夫, The magnetic duplication technique using patterned master media is a promising means of writing servo signals onto hard disks at high speed and low cost.It is expected that the direction of the applied magnetic field in the duplication process significantly influences the duplication characteristics.The objective of this paper is to clarify the influence of the oblique magnetic field out of the master plane.Experiments showed that the reproduced waveform from a slave duplicated with an oblique field is asymmetric near both edges of the protrusion of the master.The asymmetric waveform is improved by increasing the field, but the duplication characteristics with an oblique field are still inferior to those with an in-plane field.Computer simulation of the magnetization distribution of the slave duplicated with an oblique field shows that the distribution is asymmetric near both edges of the protrusion of the master, coinciding with the experimental results., The Magnetics Society of Japan
日本応用磁気学会誌, 2006年03月, ［査読有り］

A method for analysis of carrier density and mobility in polycrystalline bismuth　　　　　　　　　　　　　　　
Y. Hasegawa; Y. Ishikawa; T. Saso; H. Shirai; H. Morita; T. Komine; H. Nakamura
Physica B, 2006年02月, ［査読有り］

Influence of soft-under-layer in perpendicular media on magnetic contact duplication characteristics
A. Izumi; Y. Nagahama; T. Komine; R. Sugita; M. Nagao; M. Nishikawa; T. Yasunagi, In order to investigate the influence of SUL on duplication characteristics, we calculated magnetic field distributions around a slave medium. In the case of PFA, influence of SUL on duplication characteristics doesn't almost change even though duplication field strength increases. On the other hand, in the case of IFA, the influence of SUL on duplication characteristics is negligible even though a duplication field strength increases. The influence of SUL on duplication characteristics becomes smaller for ultra-high density perpendicular recording.
INTERMAG 2006 - IEEE International Magnetics Conference, 2006年, ［査読有り］

First-principles calculation of atomic-sized Ni nanocontacts
T. Takahashi; T. Komine; R. Sugita; Y. Hasegawa, We calculated the electronic structures of Ni nanocontact by using the first-principles band calculation, and investigated the dependence of the electronic structure on the nanocontact shape. It is expected that the large spin polarization at the center of nanocontact can be obtained in the large contact length. The small contact length can easily switch from P state to AP state in spin configuration of two ferromagnetic electrodes.
INTERMAG 2006 - IEEE International Magnetics Conference, 2006年, ［査読有り］

Reduction of contact resistance at terminations of bismuth wire arrays
Yasuhiro Hasegawa; Hiroyuki Morita; Akio Kurokouchi; Kentarou Wada; Takashi Komine, Contact resistance at the terminations of bismuth wire array of 25 mu m diameter is reduced by ion plating of a titanium interlayer 100 nm upon the wire ends. 1,000 nm-thick copper electrodes are ion plated upon the titanium. Copper probe electrodes are then attached using Pb-Sn solder. The temperature dependence of the Seebeck coefficient and resistance are measured upon heating from 25 K to 300 K and the results compared with those for the polycrystalline bulk bismuth sample. The resistivity of the micro-wire array is found to be 1.37 mu Omega m at 300 K. Based on the similarities between the temperature dependences of resistivity and Seebeck coefficient for the wire and bulk samples, contact resistance of the wires is considered to have been completely eliminated. This technique makes it possible to simultaneously estimate the resistivity and Seebeck coefficient for nano-wire arrays of thermoelectric materials., IEEE
ICT'06: XXV INTERNATIONAL CONFERENCE ON THERMOELECTRICS, PROCEEDINGS, 2006年, ［査読有り］

Numerical analysis of effective thermal conductivity in microwire array element
M. Kuraishi; T. Komine; T. Teramoto; R. Sugita; Y. Hasegawa, In this study, we have developed a three-dimensional finite element method for solving the equations of electrical and thermal flows. The 3D analysis of bulk material and wire array element was demonstrated, and electrical potential and temperature distributions were calculated in thermoelectric elements of bulk bismuth and wire array structures for various boundary conditions. The influence of wire array structure on effective thermal. conductivity of the element was discussed in this study. It was clarified that thermal exchange between bismuth wire and glass template in wire array element plays a very important role for reduction of thermal conductivity., IEEE
ICT'06: XXV INTERNATIONAL CONFERENCE ON THERMOELECTRICS, PROCEEDINGS, 2006年, ［査読有り］

Geometrical dependence of magneto resistivity in bismuth microwire arrays
Hirofumi Nakano; Yoshiaki Ishikawa; Yasuhiro Hasegawa; Hiroyuki Morita; Takashi Komine, Geometrical dependence of the magnetoresistivity using polycrystalline bismuth microwire array was measured under magnetic fields of 0-2 T at temperatures of 50-300 K, and its diameter of prepared microwire arrays were 10 and 25 mu m. Aspect ratio, defined by wire length divided by the diameter, was determined for the wire array since both edges of all wires were attached to Ti thin film layer in order to avoid contact resistance. The attachment of the layer makes it possible to estimate the resistivity of the wire arrays. Both resistivities of the wire arrays at 300 K were equal to approximately 1.35 mu Omega m and were good agreement not only at 300 K but also in temperature region of 50-300 K in the absence of a magnetic field. Although the magnetoresistivities of both samples increased in the presence of the magnetic field, the behavior of magnetoresistivity depended on wire diameter. The magnetoresistivity of the wire array with higher aspect ratio was suppressed even if the resistivities of both samples without magnetic field are equal. The difference of magnetoresistivities was remarkable in high magnetic field and low temperature region. Therefore, the thermoelectric element with high aspect ratio such as micro- and nano-wire array leads suppression of magnetoresistivity increase more than that of bulk material., IEEE
ICT'06: XXV INTERNATIONAL CONFERENCE ON THERMOELECTRICS, PROCEEDINGS, 2006年, ［査読有り］

Thermoelectric property of Cu2O thin film deposited by reactive ion plating method
H. Uchiyama; Y. Hasegawa; H. Morita; A. Kurokouchi; K. Wada; T. Komine, Cuprous oxide Cu-O thin film was deposited by Reactive Ion Plating (RIP) method, and the thermoelectric properties of Cu-O thin films were studied with varying oxygen content. Copper was evaporated by electron gun, and thin film of Cu-O was deposited with reaction in oxygen plasma. Adjusting of oxygen gas flow rate could control oxygen content of the deposited thin film. Seebeck coefficient and resistivity of the Cu2O were 0.7 mV/K and 83.5 Omega cm at room temperature, respectively. Since the resistivity was still high for the thermoelectric material, we attempted to fabricate the Cu2O thin film using copper, oxygen gas and nitrogen gas as a dopant. As a result, the Seebeck and resistivity could achieve 0.3mV/K and 2 Omega cm, which is the lowest resistivity reported without hydrogen treatment., IEEE
ICT'06: XXV INTERNATIONAL CONFERENCE ON THERMOELECTRICS, PROCEEDINGS, 2006年, ［査読有り］

Reduction of contact resistance at terminations of bismuth wire arrays
Y Hasegawa; Y Ishikawa; H Shirai; H Morita; A Kurokouchi; K Wada; T Komine; H Nakamura, Contact resistance at the terminations of bismuth wire arrays of 25-mu m diam is reduced by ion plating of a titanium interlayer 100 nm upon the wire ends. One-thousand (1000)-nm-thick copper electrodes are ion plated upon the titanium. Copper probe electrodes are then attached using Pb-Sn solder. The temperature dependences of the Seebeck coefficient and resistance are measured upon heating from 25 to 300 K and the results compared with those for the polycrystalline bulk bismuth sample. The resistivity of the microwire array is found to be 1.37 mu Omega m at 300 K. Based on the similarities between the temperature dependences of resistivity and Seebeck coefficient for the wire and bulk samples, contact resistance of the wires is considered to have been completely eliminated. This technique makes it possible to simultaneously estimate the resistivity and Seebeck coefficient for nanowire arrays of thermoelectric materials. (c) 2005 American Institute of Physics., AMER INST PHYSICS
REVIEW OF SCIENTIFIC INSTRUMENTS, 2005年11月, ［査読有り］

Micromagnetic analysis of a magnetic domain wall in 2-D and 3-D nanocontacts
T Komine; T Takahashi; S Ishii; R Sugita; T Muranoi; Y Hasegawa, We have performed micromagnetic calculations of magnetic domain walls in two-dimensional (2-D) and three-dimensional (3-D) nanocontacts and estimate the domain wall widths. The magnetic domain wall in a 3-D nanocontact is smaller than that in a 2-D nanocontact due to the larger magnetic volume available to pin the magnetization in the antiparallel configuration of the electrodes. Therefore, 3-D nanocontacts are more suitable than 2-D nanocontacts for domain wall confinement and large magnetoresistance effects., IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
IEEE TRANSACTIONS ON MAGNETICS, 2005年10月, ［査読有り］

Performance and possibility on high density bits recording by patterned master magnetic duplication　　　　　　　　　　　　　　　
M. Nagao; H. Kubota; M. Nishikawa; T. Yasunaga; T. Komine; R. Sugita
Trans. Magn. Soc. Jpn., 2005年08月, ［査読有り］

Resistivity and Seebeck coefficient measurements of a bismuth microwire array　　　　　　　　　　　　　　　
Y. Ishikawa; Y. Hasegawa; H. Morita; A. Kurokouchi; K. Wada; T. Komine; H. Nakamura
Physica B: Condensed Matter, 2005年07月, ［査読有り］

Micromagnetic calculation of the magnetization process in nanocontacts　　　　　　　　　　　　　　　
T. Komine; T. Takahashi; R. Sugita; T. Muranoi; Y. Hasegawa, マイクロマグネティックスを用いて，強磁性体ナノ接合の磁壁構造を解析し，接合部の交換結合が磁壁幅に及ぼす影響について定量化し，磁壁散乱の可能性について議論した．
Journal of Applied Physics, 2005年05月, ［査読有り］

Electronic transport properties of a bismuth microwire array in a magnetic field
Y Hasegawa; Y Ishikawa; H Morita; T Komine; H Shirai; H Nakamura, The magneto-Seebeck coefficient and magnetoresistivity of a polycrystalline bismuth microwire array were measured under magnetic fields of 0-2 T and at temperatures of 50-300 K. To avoid the influence of contact resistance between the wire array and the electrodes, bulk bismuth was used for the electrodes. In the absence of a magnetic field, the Seebeck coefficient and resistivity were -76 mu V/K and 1.8 mu Omega m at 300 K, respectively. The magneto-Seebeck coefficient for the wire array increased with the application of an external magnetic field, attributable to the precise control of impurities and carrier scattering process in the fabrication of the wire array. The phonon drag effect was observed below 100 K, with a corresponding increase in the magneto-Seebeck coefficient under high magnetic fields. However, the magnetoresistivity was also raised under higher magnetic fields, detracting from the thermoelectric properties. Through analysis of the power factor, the optimum magnetic field was determined for each temperature, revealing a trend for the optimum magnetic field to increase with temperature. The power factor was improved by a maximum factor of 1.12, achieved at 200 K and 0.25 T. Further improvements appear to be possible by eliminating the bulk bismuth employed for the electrodes. (C) 2005 American Institute of Physics., AMER INST PHYSICS
JOURNAL OF APPLIED PHYSICS, 2005年04月, ［査読有り］

磁気転写におけるスペーシング依存性　　　　　　　　　　　　　　　
杉田龍二,小峰啓史,村野井徹夫,西川正一,安永正,長尾信
日本応用磁気学会誌, 2005年03月, ［査読有り］

有限要素法を用いたフラックスガイド型半導体磁気抵抗素子の解析
高山裕樹,小峰啓史,杉田龍二,村野井徹夫,長谷川靖洋, We investigate the magnetoresistance of a magnetoresistive element consisting of a nonmagnetic semiconductor, four electrodes, and a metallic shunt, with varying locations of the voltage electrodes. The optimum location of the voltage electrodes is estimated from MR ratios calculated by using the finite element method. The MR ratio of 6.9%, which was obtained at an applied magnetic field of 0.005 T for an MR element with asymmetrical voltage electrodes separated by a distance of 25 nm, is higher than that for the MR element with symmetrical electrodes. In order to improve the MR ratio at a low applied field, a flux-guide-type MR element is proposed in this study. An MR ratio of 124% at an applied field of 0.005 T was obtained for a flux-guide-type element with asymmetrical electrodes., The Magnetics Society of Japan
日本応用磁気学会誌, 2005年03月, ［査読有り］

磁性体ナノ接合部における磁壁構造の数値解析
小峰啓史; 高橋朋広; 杉田龍二; 村野井徹夫; 長谷川靖洋, 強磁性体ナノ接合の磁壁構造をマイクロマグネティックスにより解析し，Ｈ型強磁性体の接合形状と磁壁幅の関係を明らかにした．, The Magnetics Society of Japan
日本応用磁気学会誌, 2005年02月, ［査読有り］

Investigation of physical and electric properties of silver pastes as a binder for thermoelectric materials
Atsushi Suzuki; Yasuhiro Hasegawa; Yoshiaki Ishikawa; Takashi Komine; Hiroyuki Morita; Hajime Shirai, The physical and electric properties of several silver pastes, Pb-Sn solder, and indium were systematically investigated as potential binders for attaching electrodes to bismuth-based bulk or nanowire array thermoelectric elements. Scanning electron microscopy observations and x-ray diffraction surface measurements of the silver pastes were performed and the temperature and magnetic field dependence of the resistance were measured to characterize their electrical properties from 300 K down to 15 K and from 0 to 1 T at 15 K, respectively. The silver pastes were not reactive with bismuth and hence were found to be potentially useful as electrically conductive adhesives with bismuth-based materials. The properties of each of the binders were quite different
the typical size of the particles in the silver pastes before solidification were distributed in the range from 3 nm to 20 μm, and the size strongly affected the resistances of the silver pastes, which were distributed over 2 and 3 orders of magnitude at 300 and 15 K, respectively. Therefore, an appropriate selection of binder must be made for a specific purpose, based on the measurement results. For use with bismuth-based thermoelectric materials, the silver nanopaste is a strong candidate binder because it is far superior to other the binders examined in terms of its resistance properties and magnetic field dependence. ©2005 American Institute of Physics.
Review of Scientific Instruments, 2005年01月, ［査読有り］

Micromagnetic analysis of a magnetic domain wall in a nanocontact
T. Komine; T. Takahashi; S. Ishii; R. Sugita; T. Muranoi; Y. Hasegawa, IEEE Computer Society
INTERMAG ASIA 2005: Digests of the IEEE International Magnetics Conference, 2005年

Electronic transport properties of a bismuth microwire array in a magnetic field
Y Hasegawa; Y Ishikawa; H Morita; T Komine; H Shirai; H Nakamura, The magneto-Seebeck coefficient and magneto-resistivity of a polycrystalline bismuth microwire array were measured under magnetic fields of 0 to 2 Tesla and at temperatures of 50 to 300 K. To avoid the influence of contact resistance between the wire array and the electrodes, bulk bismuth was used for the electrodes. In the absence of a magnetic field, the Seebeck coefficient and resistivity were -76 mu V/K and 1.8 mu Omega m at 300 K, respectively. The rnagneto-Seebeck coefficient for the wire array increased with the application of an external magnetic field, attributable to the precise control of impurities and carrier scattering process in the fabrication of the wire array. The phonon drag effect was observed below 100 K, with a corresponding increase in the rnagneto-Seebeck coefficient under high magnetic fields. However, the magneto-resistivity was also raised under higher magnetic fields, detracting from the thermoelectric properties. Through analysis of the power factor, the optimum magnetic field was determined for each temperature, revealing a trend for the optimum magnetic field to increase with temperature. The power factor was improved by a maximum factor of 1.12, achieved at 200 K and 0.25 Tesla. Further improvements appear to be possible by eliminating the bulk bismuth employed for the electrodes., IEEE
ICT: 2005 24th International Conference on Thermoelectrics, 2005年, ［査読有り］

Electronic transport properties of a bismuth microwire array in a magnetic field
Y Hasegawa; Y Ishikawa; H Morita; T Komine; H Shirai; H Nakamura, The magneto-Seebeck coefficient and magneto-resistivity of a polycrystalline bismuth microwire array were measured under magnetic fields of 0 to 2 Tesla and at temperatures of 50 to 300 K. To avoid the influence of contact resistance between the wire array and the electrodes, bulk bismuth was used for the electrodes. In the absence of a magnetic field, the Seebeck coefficient and resistivity were -76 mu V/K and 1.8 mu Omega m at 300 K, respectively. The rnagneto-Seebeck coefficient for the wire array increased with the application of an external magnetic field, attributable to the precise control of impurities and carrier scattering process in the fabrication of the wire array. The phonon drag effect was observed below 100 K, with a corresponding increase in the rnagneto-Seebeck coefficient under high magnetic fields. However, the magneto-resistivity was also raised under higher magnetic fields, detracting from the thermoelectric properties. Through analysis of the power factor, the optimum magnetic field was determined for each temperature, revealing a trend for the optimum magnetic field to increase with temperature. The power factor was improved by a maximum factor of 1.12, achieved at 200 K and 0.25 Tesla. Further improvements appear to be possible by eliminating the bulk bismuth employed for the electrodes., IEEE
ICT: 2005 24th International Conference on Thermoelectrics, 2005年

Magneto-Seebeck coefficient of a bismuth microwire array in a magnetic field
Y Hasegawa; Y Ishikawa; T Komine; TE Huber; A Suzuki; H Morita; H Shirai, The enhancement of the magneto-Seebeck coefficient of a bismuth microwire array under a magnetic field is measured at temperatures from 45 to 295 K. The measured magneto-Seebeck coefficient exhibits a peak at a certain magnitude of magnetic field, with the peak shifting to higher magnetic fields and becoming broader with increasing temperature. The results show that the magneto-Seebeck coefficient can be improved by approximately 20% by applying an appropriate external magnetic field and temperature. The Boltzmann equation with a relaxation-time approximation is solved numerically to determine the magnetic field and temperature dependences of the magneto-Seebeck coefficient for the bismuth microwire array. The experimental results are compared with calculations, and the two sets of results are shown to be in very good agreement, clarifying the mechanisms contributing to the magneto-Seebeck coefficient for bismuth. The wire array structure is thus suitable for enhancing the thermoelectric properties of materials in a magnetic field. (C) 2004 American Institute of Physics., AMER INST PHYSICS
APPLIED PHYSICS LETTERS, 2004年08月, ［査読有り］

Analysis of Carrier Density and Mobility of Polycrystalline Bi Dominated by Impurity Scattering of Carrier　　　　　　　　　　　　　　　
Yoshiaki Ishikawa; Yasuhiro Hasegawa; Hiroyuki Morita; Takashi Komine; Hajime Shirai
The 23rd International Conference on Thermoelectrics, 2004年07月

磁気転写特性のマスター磁性層厚依存性　　　　　　　　　　　　　　　
杉田 龍二,小峰 啓史,村野井 徹夫,西川 正一,安永 正,長尾 信
日本応用磁気学会誌, 2004年01月, ［査読有り］

Numerical calculation of magneto-seebeck coefficient of bismuth under a magnetic field
Y Hasegawa; T Komine; Y Ishikawa; A Suzuki; H Shirai, Seebeck and Nernst coefficients were numerically calculated by solving the Boltzmann equation with relaxation time approximation for bismuth under a magnetic field as functions of the products of cyclotron frequency (omega(c)) and relaxation time (tau(0)), taking into consideration the scattering process of carriers as a function of energy. The relationship between omega(c)tau(0) and magnitude of the magnetic field was derived from the definition of mobility, and each coefficient was estimated as a function of the magnetic field. The magneto-Seebeck coefficient was estimated by the addition of the Seebeck coefficient to the Nernst coefficient, and the contribution of thermoelectric effect in the presence of the magnetic field was dominant, being derived from the Seebeck effect. The magnetic field and temperature dependences of the magneto-Seebeck coefficient were evaluated by the use of a two-carrier model and mobility of single-crystal bismuth. The results show that the magneto-Seebeck coefficient can be improved by a factor of 1.3 to 1.4 in the presence of a magnetic field to control the scattering process of the carriers., INST PURE APPLIED PHYSICS
JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS, 2004年01月, ［査読有り］

Thermoelectric characteristics of Si/Ge superlattice thin films at temperatures less than 300 K
M Hamabe; H Takahashi; S Yamaguchi; T Komine; T Eura; H Okumura; Y Okamoto; J Morimoto, We have studied the thermoelectric characteristics of Si/GeAu superlattice thin films at temperatures ranging from 290 K to 75 K and compared them to those of the SiGeAu alloy thin film. In the annealed Si/GeAu superlattice, the electrical resistivity was lower than that of the unannealed Si/GeAu superlattice at all temperatures. The annealed Si/GeAu superlattice showed a high thermoelectric power of 105 muV/K at 290 K. At temperatures less than 200 K, however, the polarity of the thermoelectric power of the unannealed Si/GeAu superlattice switched from positive to negative and a large negative thermoelectric power of -4.6 mV/K was attained at 80 K. On the other hand, the characteristics of all samples showed no magnetic field effect at all temperatures. To explain the causes of the extremely small variations in the characteristics by the magnetic field effects, we calculated the transport coefficients for the SiGeAu alloy using the two-band parabolic model, and compared them to those of experimentally measured values. When a large amount of acceptor concentration from Au doping and the very low carrier mobility were assumed, similar transport coefficients to the measured ones resulted., INST PURE APPLIED PHYSICS
JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS, 2003年11月, ［査読有り］

Numerical analysis of thermoelectric properties of bismuth under magnetic field
T Komine; Y Ishikawa; A Suzuki; H Shirai; Y Hasegawa, We study the anisotropic thermoelectric properties of bismuth associated with many-valley bandstructure in magnetic field. In order to obtain the thermoelectric properties of anisotropic materials under a magnetic field, we numerically solved the Boltzmann equation in tensor form. The magnetic field dependences of Seebeck coefficient tensor and conductivity tensor are calculated in various directions of magnetic field. The ratio of effective mass along the longest axis and the shortest axis of each ellipsoid is sensitive for the magnetic field effect of thermoelectric properties. The thermoelectric properties of bismuth under magnetic field are calculated varying relaxation time and Fermi energy, which concern purity of bismuth sample. The lower relaxation time, which corresponds to neutral impurity concentration, makes the optimum strength of magnetic field higher. The higher Fermi energy corresponding to doping impurity causes larger magneto-Seebeck coefficient., IEEE
TWENTY-SECOND INTERNATIONAL CONFERENCE ON THERMOELECTRICS, PROCEEDINGS ICT '03, 2003年

Seebeck coefficient and resistivity measurement of polycrystalline Bi in a magnetic field
Y Ishikawa; A Suzuki; T Komine; H Shirai; Y Hasegawa, Seebeck coefficient and resistivity of a polycrystalline Bi sample were measured from 15 to 300 K in a magnetic field. The measured Seebeck coefficient at 15 K was -10 muV/K at 0 Tesla; however, the Seebeck coefficient enormously varied as a function of magnetic field and was over -1 mV/K at 1.5 Tesla. The Hall coefficient was measured by Van der Pauw method in order to evaluate the carrier density for estimating the mechanism of varying Seebeck coefficient at 15 K, and the carrier density decreased by a factor of 1/30 at 1.5 Tesla. It was shown that one reason for the variation of the Seebeck coefficient was the influence of phonon drag effect, even for polycrystalline Bi. A large Seebeck coefficient was observed below the Debye temperature of Bi in the magnetic field. The resistivity at 15 K also enormously increased in the transverse magnetic field due to the decreased carrier density, and the ratio of the increase of the resistivity compared to the case for no magnetic field was approximately 1000 times at 1.5 Tesla and decreased with increasing temperature. The increase in the resistivity influenced the phonon drag effect and increased the Seebeck coefficient., IEEE
TWENTY-SECOND INTERNATIONAL CONFERENCE ON THERMOELECTRICS, PROCEEDINGS ICT '03, 2003年

Investigation on binder for thermoelectric module
A Suzuki; Y Ishikawa; T Komine; H Shirai; Y Hasegawa, Physical and electric properties of several silver pastes were investigated to replace conventional Pb-Sn solder used in thermoelectric module. The melting point of the conventional solder is relatively low and its temperature stability is insufficient for use in a high temperature region. Therefore silver paste (epoxy) is a candidate instead of the Pb-Sn solder. A copper block was glued to electrodes using several silver pastes to measure the electric property, and the resistances were measured by four-probe method from 15K to 300K, and the magnetic field dependence was also investigated. The results showed that the resistance of a silver paste adopted nano particles (called silver nano paste) was lower than that of any binders used. We concluded that the nano paste is a candidate as a binder for conventional thermoelectric modules. Besides the nano paste has a possibility to be used on thermoelectric modules in the high temperature region., IEEE
TWENTY-SECOND INTERNATIONAL CONFERENCE ON THERMOELECTRICS, PROCEEDINGS ICT '03, 2003年

Thermoelectric characteristics of Si/Ge superlattice thin film at low temperature
M Hamabe; H Takahashi; S Yamaguchi; T Komine; T Eura; Y Okamoto; J Morimoto, We have been studied thermoelectric characteristics of Si / (Au-doped Ge) superlattice thin films at temperatures from room temperature (RT) to low temperatures less than 100 K and compared these to those of Si and (Au + Ge) alloy thin film. In the Si / (Ge + Au) superlattice after heating process, the electric resistivity decreased at all temperature. This annealed Si / (Ge + Au) superlattice showed the high thermoelectric power of 105 muV/K at 290 K, compared with the unannealed Si / (Ge + Au) or the alloy film. At temperatures less than 200 K, however, the thermoelectric power of the unannealed Si / (Ge + Au) switched polarities from positive to negative and reached -4.6 mV/K at 80 K. This large negative thermoelectric power at low temperature was not observed in the annealed Si / (Ge + Au) or the alloy film. On the other hand, magnetic field characteristics of all samples showed no effect at 100 K, 200 K or 290 K. This was explained using the two-band parabolic model calculation, assuming that a large amount of Au-doping caused a very low carrier mobility., IEEE
XXI INTERNATIONAL CONFERENCE ON THERMOELECTRICS, PROCEEDINGS ICT '02, 2002年

Research and development on a thermoelectric power generating system using low-calorie exhaust gas(final)
T Eura; T Komine; Y Hasegawa; A Takata; F Katsuki; M Katoh; K Nakao; K Utsumi, The U-type Fe-Si porous thermoelectric devices (ex. 0 30mm X 20mm) were developed to recover electric power by reciprocating combustion of low calorie exhaust gas without any city gases and any pollution. The output power was finally improved to 80mW similar to 90mW under the critical equivalent ratio less than 0.1.[1]similar to[4]., IEEE
TWENTIETH INTERNATIONAL CONFERENCE ON THERMOELECTRICS, PROCEEDINGS, 2001年

First-principle band calculation of ruthenium for various phases
S Watanabe; T Komine; T Kai; K Shiiki, The total energies and the magnetic moments of Ru for HCP, BCC, FCC, BCT structures were calculated by using a first-principle full-potential linearized augmented plane-wave (FLAPW) method based on the generalized gradient approximation (GGA). HCP has the lowest energy among the structures calculated, which agrees with the experimental result that HCP is the equilibrium phase of Ru. The total energy of BCT Ru has the local minimum at c/a = root 2 (FCC) with a = 5.13 au, c = 7.25 au and cia = 0.83 with a = 6.15 au, c = 5.11 au. It is pointed out that: these phases are possibly metastable. The BCC structure, which corresponds to BCT with a = c = 5.78 au, is unstable because it is at a saddle point of the total energy. BCT Ru of cia < 1 has a magnetic moment at the stable volume. (C) 2000 Elsevier Science B.V. All rights reserved., ELSEVIER SCIENCE BV
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 2000年10月, ［査読有り］

Self-consistent first-principles calculations based on the embedded atomic sphere method
T Komine; K Shiiki, We present a self-consistent embedded atomic sphere method. The embedded atomic sphere method is linearized for the easy calculation of wave functions. The coefficients of linearized basis sets inside spheres are determined to satisfy the continuity of the logarithmic derivatives between the inside and the outside of the sphere. We have applied this method to the hydrogen atom. It is shown that the calculated energy converges as the ratio of the sphere radius to the grid spacing increases. We implemented a self-consistent calculation for analysis of fee hydrogen and the H-2 molecule. The calculated density of states of fee hydrogen and the equilibrium interatomic distance of the H-2 molecule were found to be in good agreement with the results of conventional methods., AMER PHYSICAL SOC
PHYSICAL REVIEW B, 2000年03月, ［査読有り］

A theoretical study of interfacial structure of Co/Cu and Co/Pd multilayers
Y Fujii; T Komine; T Kai; K Shiiki, The electronic structures and energies of Co/Cu and Co/Pd multilayers with abrupt or mixed interfaces have been calculated using the linear muffin-tin orbital method in the atomic sphere approximation. The mixed interface is modelled by exchanging atoms between Co layers and Cu (Pd) layers. The calculated total energies of Co/Cu multilayers with mixed interfaces are higher than those of Co/Cu multilayers with abrupt interfaces. The calculated total energies of Co/Pd multilayers with mixed interfaces are lower than those of Co/Pd multilayers with abrupt interfaces. Stable interface structure appears to be abrupt in Co/Cu multilayers and mixed in Co/Pd multilayers, as revealed by experimental observations. Total-energy differences between the multilayer with abrupt interfaces and the multilayer with mixed interfaces are caused by Co 3d-band narrowing for Co/Cu multilayers and Pd spin polarizations for Co/Pd multilayers., IOP PUBLISHING LTD
JOURNAL OF PHYSICS-CONDENSED MATTER, 1999年12月, ［査読有り］

Self-consistent embedded atomic sphere method for calculating electronic structure of non-periodic systems
T. Komine; K. Shiiki, We present a new method for calculating the electronic structures of non-periodic system. The atomic sphere is embedded into the finite difference grids. The wavefunction inside atomic spheres is expanded into the spherical wave. The radial basis is linearized on energy. The coefficients of linearized basis sets inside sphere are determined to satisfy the continuity of the logarithmic derivatives between inside and outside sphere. We applied this method to the transition metal and tested it., Progress of Theoretical Physics
Progress of Theoretical Physics, Supplement, 1999年09月, ［査読有り］

Effect of stabilizing fields on magnetization process of magnetoresistive element
Y Hirata; T Komine; K Shiiki, Micromagnetic simulation using the Landan-Lifshitz-Gilbert equation is employed to study the magnetization process of a simple magnetoresistive (MR) element stabilized by a magnetic field at edges in the track width direction. The magnetization process of the MR element exhibits irreversible processes due to the presence of closure domains generated by an external field. In the absence of a stabilizing field, there exist two anomalous behaviors in the magnetization process. The closure domain generated at the track edges boundaries makes the magnetization complex and causes hysteresis, while the magnetization state at zero external field is reproducible when the closure domain is generated at the edges of the MR element. The stabilizing field suppresses the generation of closure domains and hysteresis even if closure domains appear at tract width boundaries., JAPAN J APPLIED PHYSICS
JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS, 1997年10月, ［査読有り］

Micromagnetics of soft magnetic thin films in presence of defects
T Komine; Y Mitsui; K Shiiki, We solve numerically the Landau-Lifshitz-Gilbert equation and calculate the magnetization in a magnetic film including a nonmagnetic defect for two initial magnetization slates consisting of circular structure with 4 domains and 7 domains. The defect at the vortex wall restrains the magnetization temporarily but the vortex wall comes out of the defect beyond a critical applied field. This critical field increases as the defect size becomes large. The defect at the film side fixes the magnetization at the film edge. The edge defect leads to a reproducible magnetization state inside the film, though a locally stable structure appears for the magnetic thin film without defects. It seems that the defect may improve the stability of the magnetic thin film head. (C) 1995 American Institute of Physics., AMER INST PHYSICS
JOURNAL OF APPLIED PHYSICS, 1995年12月, ［査読有り］

〔主要な業績〕LLGシミュレーション入門
小峰啓史
まぐね, 2023年04月01日, ［査読有り］
筆頭著者

Bi-Sbの磁場中の熱電物性測定における試料形状の影響
村田正行; 鈴木真理; 青山佳代; 長瀬和夫; 大島博典; 山本淳; 長谷川靖洋; 小峰啓史
応用物理学会秋季学術講演会講演予稿集(CD-ROM), 2023年

イオンの拡散制御による新規物質開発
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応用物理学会秋季学術講演会講演予稿集(CD-ROM), 2020年

直径400nm級Biナノワイヤーの熱・電流磁気効果
村田正行; 冨岡平祐; 冨岡平祐; 青山佳代; 山本淳; 長谷川靖洋; 小峰啓史
応用物理学会秋季学術講演会講演予稿集(CD-ROM), 2019年

強磁性トンネル接合における電圧誘起磁気キャパシタンス効果
海住英生; 三澤貴浩; 長浜太郎; 小峰啓史; 北上修; 藤岡正弥; 西井準治; XIAO Gang
日本磁気学会学術講演概要集, 2018年

薄膜エッジを利用したNi₇₈Fe₂₂/Alq₃/Ni₇₈Fe₂₂ナノ接合の作製とその構造・電気伝導特性
三澤貴浩; 森澄人; 小峰啓史; 星野哲久; 芥川智行; 藤岡正弥; 海住英生; 西井準治
応用物理学会秋季学術講演会講演予稿集(CD-ROM), 2016年09月01日

漏洩磁場を利用したスピン量子十字デバイスの構造・磁気特性
海住英生; 森澄人; 三澤貴浩; 小峰啓史; 中村晃輔; 藤岡正弥; 西井準治
応用物理学会春季学術講演会講演予稿集(CD-ROM), 2016年03月03日

磁場中の量子ポイントコンタクトにおける電子状態と電気伝導
青野 友祐; 川村 稔; 大野 圭司; 小峰 啓史
日本物理学会講演概要集, 2016年

バルク熱電材料のゼーベック係数・抵抗率・熱拡散率の同時測定
本間亮英; 寺門宏樹; 長谷川靖洋; 村田正行; 山本淳; 小峰啓史; 森田寛之
応用物理学会春季学術講演会講演予稿集(CD-ROM), 2015年

焼結法により作製したBi-Sb合金の磁場中の熱電物性
村田正行; 山本淳; 長谷川靖洋; 小峰啓史
応用物理学会春季学術講演会講演予稿集(CD-ROM), 2015年

22pm1-E5 石英ガラスを利用したBiナノワイヤーの作製と熱電物性の評価
村田 正行; 山本 淳; 長谷川 靖洋; 小峰 啓史
マイクロ・ナノ工学シンポジウム, 2014年10月20日

直径700nm Biナノワイヤーのホール係数測定とキャリア移動度評価
村田正行; 山本淳; 長谷川靖洋; 小峰啓史
応用物理学会秋季学術講演会講演予稿集(CD-ROM), 2014年

Bi-Sb系バルク材料の作製と熱電物性の評価
村田正行; 山本淳; 長谷川靖洋; 小峰啓史
応用物理学会秋季学術講演会講演予稿集(CD-ROM), 2014年

鋳型圧入法によるBiナノワイヤーの開発と熱電物性の評価
村田正行; 山本淳; 寺門宏樹; 本間亮英; 長谷川靖洋; 小峰啓史
応用物理学会秋季学術講演会講演予稿集(CD-ROM), 2014年

23aTL-2 単結晶ビスマスナノワイヤーのShubnikov-de Haas振動(23aTL 量子ホール効果(整数量子ホール効果),領域4(半導体,メゾスコピック系・局在))
常見 文昭; 村田 正行; 長谷川 靖洋; 小峰 啓史; 遠藤 彰
日本物理学会講演概要集, 2011年

熱電材料の磁場効果
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日本磁気学会研究会資料 = Bulletin of Topical Symposium of the Magnetics Society of Japan, 2010年08月03日

CoPt垂直マスターの転写特性における組成依存性
小野瀬勝,田中康貴,川崎龍太,小峰啓史,杉田龍二
電子情報通信学会技術研究報告, 2010年07月

ECC媒体への垂直磁気転写シミュレーション
川前武士,村越拓治,小峰啓史,杉田龍二
電子情報通信学会技術研究報告, 2010年07月

垂直磁気転写によるサーボ信号記録
杉田龍二,小峰啓史
電子情報通信学会技術研究報告, 2010年06月

磁性細線における磁壁移動の電流パルス依存性
小峰啓史,村上宏,杉田龍二
電子情報通信学会技術研究報告, 2009年10月

拡大モデルによる垂直磁気転写解析
田辺和博,齋藤俊明,N.Sheeda,小峰啓史,杉田龍二
電子情報通信学会技術研究報告, 2008年07月

強磁性ナノワイヤにおける切り込みが磁壁移動に及ぼす影響
村上宏,小峰啓史,杉田龍二
電子情報通信学会技術研究報告, 2008年07月

Influence of spacing between master and slave media on magnetic duplication characteristics for perpendicular recording media
T.Murata; A.Izumi; S.Okami; N.Sheeda; T.Komine; R.Sugita
電子情報通信学会技術研究報告, 2007年08月01日, ［査読有り］

蒸着テープを用いた垂直磁気転写解析
Nural Sheeda,岡見智史,小峰啓史,杉田龍二
電子情報通信学会技術研究報告, 2007年06月

Biナノワイヤー熱電素子の開発
長谷川靖洋; 中野博文; 神戸勇貴; 森田寛之; 小峰啓史; 中村浩章
応用物理学関係連合講演会講演予稿集, 2007年

BiSb合金のバンド構造が磁気ゼーベック係数に与える影響
寺本貴之; 山本真司; 倉石正寛; 小峰啓史; 長谷川靖洋; 中村浩章; 杉田龍二
応用物理学関係連合講演会講演予稿集, 2007年

熱電材料の磁場効果
小峰 啓史; 長谷川 靖洋; 中村 浩章
まぐね = Magnetics Japan, 2006年10月01日

熱電材料の磁場効果
小峰啓史; 長谷川靖洋,中村浩章
まぐね, 2006年10月01日

面内磁気記録媒体への短ビットの磁気転写の性能と可能性
長尾信,久保田秀幸,西川正一,安永正,小峰啓史,杉田龍二
電子情報通信学会技術研究報告, 2006年07月

斜め方向転写磁場が転写特性に及ぼす影響
岡見智史,富川智史,小峰啓史,杉田龍二
電子情報通信学会技術研究報告, 2006年07月

垂直磁気記録媒体へのサーボパターンの磁気転写の可能性
西川正一,若松啓史,市川健次,宇佐利裕,石岡利英,安永正,小峰啓史,杉田龍二
電子情報通信学会技術研究報告, 2006年07月

垂直磁気転写シミュレーション
村田剛史,和泉昭彦,小峰啓史,杉田龍二
電子情報通信学会技術研究報告, 2006年07月

Performance and potential of high-density bit recording using patterned master contact duplication
M.Nagao; H.Kubota; M.Nishikawa; T.Yasunaga; T.Komine; R.Sugita
FUJIFILM RESEARCH & DEVELOPMENT, 2006年03月

高効率熱電変換材料の現状と展望
梶川武信; 堀康彦; 山本淳; 生駒圭子; 今井義博; 江浦隆; 越後亮三; 小原春彦; 鎌田策雄; 木谷文一; 小峰啓史; 佐々裕美; 篠原嘉一; 丹治よう典; 津吉彰; 長谷川靖洋; 藤井一宏; 舟橋良次; 松山喜代志; 水上裕之; 吉野淳二; 藤田顕二郎; 阿武宏明; 申ウソク; 山中伸介; 永吉浩; 上村欣一; 河本邦仁; 陳立東; 西田勲夫; 東泉; 松原覚衛
電気学会技術報告, 2006年

マイクロワイヤー熱電素子の開発
長谷川靖洋; 石川最朗; 森田寛之; 小峰啓史; 中村浩章
応用物理学関係連合講演会講演予稿集, 2005年

磁場中におけるマイクロワイヤーアレイ素子の熱電特性の計測
石川最朗; 長谷川靖洋; 小峰啓史; 森田寛之; 中村浩章
応用物理学関係連合講演会講演予稿集, 2005年

実効的な磁気ゼーベック係数に及ぼす形状効果の数値解析
小峰啓史; 長谷川靖洋; 石川最朗; 森田寛之; 中村浩章; 杉田龍二; 村野井徹夫
応用物理学関係連合講演会講演予稿集, 2005年

半導体磁気抵抗効果を利用した再生ヘッド
高山 裕樹; 小峰 啓史; 杉田 龍二; 村野井 徹夫
電子情報通信学会技術研究報告. MR, 磁気記録, 2004年10月08日

磁気転写特性のスペーシング依存性
金子朝子,小峰啓史,杉田龍二,村野井徹夫,西川正一,安永正,長尾信
電子情報通信学会技術研究報告, 2004年10月01日, ［査読有り］

磁気転写特性のスペーシング依存性
金子朝子,小峰啓史,杉田龍二,村野井徹夫,西川正一,安永正,長尾信
電子情報通信学会技術研究報告, 2004年10月01日, ［査読有り］

半導体磁気抵抗効果を利用した再生ヘッド
高山裕樹,小峰啓史,杉田龍二,村野井徹夫
電子情報通信学会技術研究報告, 2004年10月01日, ［査読有り］

強磁性ナノワイヤ構造の第一原理計算
高橋 朋広; 小峰 啓史; 杉田 龍二; 村野井 徹夫; 長谷川 靖洋
日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 2004年09月21日

磁性体ナノ接合の磁化過程
小峰 啓史; 長谷川 靖洋; 杉田 龍二; 村野井 徹夫
日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 2004年09月21日

磁性体を組み合わせた半導体磁気抵抗素子
高山 裕樹; 小峰 啓史; 杉田 龍二; 村野井 徹夫; 長谷川 靖洋
日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 2004年09月21日

磁気転写特性のマスター磁性層厚依存性
杉田 龍二; 小峰 啓史; 村野井 徹夫; 西川 正一; 安永 正; 長尾 信
日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 2003年09月01日

6pSB-3 低温におけるSi/Ge超格子薄膜の熱電特性(輸送現象,励起子,アモルファス,領域4)
浜辺 誠; 高橋 英昭; 中村 圭二; 山口 作太郎; 小峰 啓史; 江浦 隆; 岡本 庸一; 守本 純
日本物理学会講演概要集, 2002年08月13日

23pPSA-4 Embedded Atomic Sphere法による遷移金属薄膜の電子状態計算
小峰 啓史; 石井 望; 兼吉 亮成; 五十嵐 雅明; 椎木 一夫
日本物理学会講演概要集, 2000年09月10日

24pPSB-4 第一原理バンド計算によるスピントンネル磁気抵抗効果に関する研究
海住 英生; 小峰 啓史; 椎木 一夫
日本物理学会講演概要集, 2000年09月10日

24pPSB-3 第一原理バンド計算によるNi薄膜の磁性に関する研究
兼吉 亮成; 五十嵐 雅明; 小峰 啓史; 椎木 一夫
日本物理学会講演概要集, 2000年09月10日

25aPS-18 Embedded Atomic Sphere法による還移金属薄膜の電子状態と磁性
小峰 啓史; 石井 望; 椎木 一夫
日本物理学会講演概要集, 2000年03月10日

24pPSB-27 第一原理バンド計算によるスピントンネル磁気抵抗効果に関する研究
海住 英生; 小峰 啓史; 椎木 一夫
日本物理学会講演概要集, 2000年03月10日

26pPSA-51 強磁性bct Ruの可能性
渡辺 正一; 小峰 啓史; 椎木 一夫
日本物理学会講演概要集, 1999年09月03日

25aPS-6 Embedded Atomic Sphere法の非周期系への適用
小峰 啓史; 椎木 一夫
日本物理学会講演概要集, 1999年09月03日

28a-PS-95 Mo基板上Ru二原子層の構造安定性及び磁性
渡辺 正一; 小峰 啓史; 椎木 一夫
日本物理学会講演概要集, 1999年03月15日

30p-PSA-27 Self-consistent calcuation for electronic structure using Full-Potential Embedded Atomic Sphere Method
小峰 啓史; 椎木 一夫
日本物理学会講演概要集, 1999年03月15日

26p-PSA-7 反強磁性酸化物NiOにおける結晶構造・組成の交換結合磁界への影響
合田 亘; 小峰 啓史; 椎木 一夫
日本物理学会講演概要集, 1998年09月05日

30a-PS-22 界面mixingを考慮したCo/Cu人工格子の第一原理計算
藤井 裕雄; 小峰 啓史; 甲斐 正; 椎木 一夫
日本物理学会講演概要集, 1998年03月10日

MR素子の磁化過程
平田 幸伸; 小峰 啓史; 椎木 一夫
日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 1996年09月01日

端部の欠陥が軟磁性薄膜の磁化過程に及ぼす影響
小峰 啓史; 椎木 一夫
日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 1995年09月01日

動的インダクタにおける超強結合マグノン‐ポラリトン　　　　　　　　　　　　　　　
千葉貴裕; 小峰啓史; 青野友祐
第71回 応用物理学会春季学術講演会, 2024年03月
202403, 202403

c-Al2O3基板上へのMg3Sb2薄膜のエピタキシャル成長における基板温度の影響　　　　　　　　　　　　　　　
切通望; 鮎川瞭人; 坂根駿也; 小峰啓史; 鵜殿治彦
第71回 応用物理学会春季学術講演会, 2024年03月
202403, 202403

〔主要な業績〕Microwave Transmission Theory for Ultrastrong-Coupled Magnon-Polariton in Dynamical Inductors　　　　　　　　　　　　　　　
T. Chiba; T. Komine; and T. Aono
Symposium on Frontier of Terahertz Science X, 2023年11月
202312, 202312

〔主要な業績〕Microwave Transmission Theory for On-Chip Ultrastrong-Coupled Magnon-Polariton in Dynamical Inductors　　　　　　　　　　　　　　　
T. Chiba; T. Komine; and T. Aono
The 7th Symposium for the Core Research Clusters for Materials Science and Spintronics and the 6th Symposium on International Joint Graduate Program in Materials Science and Spintronics, 2023年11月
202311, 202312

〔主要な業績〕Numerical analysis of write-error-rate in magnetic-topological-insulator-based devices with voltage-controlled magnetization switching　　　　　　　　　　　　　　　
T. Komine; and T. Chiba
The 68th Annual Magnetism and Magnetic Materials (MMM) Conference, 2023年11月
202310, 202311

〔主要な業績〕Magnetic printing characteristics of burst signals by using double magnet mater media　　　　　　　　　　　　　　　
T. Komine
The 68th Annual Magnetism and Magnetic Materials (MMM) Conference, 2023年11月
202310, 202311

〔主要な業績〕ダブルマグネット型マスター媒体によるバースト信号の転写特性　　　　　　　　　　　　　　　
小峰啓史
第47回 日本磁気学会学術講演会, 2023年09月
202309, 202309

〔主要な業績〕アモルファスTbFeCo 磁性薄膜における熱電テンソルの組成依存性　　　　　　　　　　　　　　　
小峰啓史,安藤亮
第47回 日本磁気学会学術講演会, 2023年09月
202309, 202309

〔主要な業績〕トポロジカル絶縁体/磁性絶縁体二層膜における強結合磁気共鳴　　　　　　　　　　　　　　　
千葉貴弘,小峰啓史,青野知祐
第47回 日本磁気学会学術講演会, 2023年09月
202309, 202309

〔主要な業績〕Voltage-control of magnetization dynamics by using topological insulators　　　　　　　　　　　　　　　
T. Komine; T. Chiba
第47回 日本磁気学会学術講演会 / Symposium on "Advanced local probe techniques in nanoscaled magnetism, 2023年09月, ［招待有り］
202309, 202309

〔主要な業績〕同一試料を用いたBi-Sbの磁場中熱電性能指数の評価　　　　　　　　　　　　　　　
村田正行,鈴木真理,青山佳代,長瀬和夫,大島博典,山本淳,長谷川靖洋,小峰啓史
第20回日本熱電学会学術講演会（TSJ2023）, 2023年09月
202309, 202309

〔主要な業績〕Bi-Sbの磁場中の熱電物性測定における試料形状の影　　　　　　　　　　　　　　　
村田正行,鈴木真理,青山佳代,長瀬和夫,大島博典,山本淳,長谷川靖洋,小峰啓史
第84回 応用物理学会秋季学術講演会, 2023年09月
202309, 202309

〔主要な業績〕TbFeCo磁性薄膜の異常ネルンスト効果に寄与する因子分析　　　　　　　　　　　　　　　
安藤亮,小峰啓史
第84回 応用物理学会秋季学術講演会, 2023年09月
202309, 202309

〔主要な業績〕Write-error rate estimation of voltage-controlled magnetization switching in a magnetic-topological-insulator-based device　　　　　　　　　　　　　　　
T Komine; S. Watahiki; T. Chiba
2023 Intermag Conference, 2023年05月, IEEEE, MSJ
202305, 202305

Room-temperature magnetoresistance in nanojunctions consisting of C8-BTBT molecules sandwiched between two magnetic thin-film edges　　　　　　　　　　　　　　　
M. Matsuzaka; Y. Sasaki; K. Hayashi; T. Misawa; T. Komine; T. Akutagawa; M. Fujioka; J. Nishii; and H. Kaiju
2023 Intermag Conference, 2023年05月, IEEEE, MSJ
202305, 202305

磁性トポロジカル絶縁体素子の電圧制御磁化反転における書き込みエラー率の数値解析　　　　　　　　　　　　　　　
小峰啓史,綿引詩門,千葉貴裕
第70回 応用物理学会春季学術講演会, 2023年03月
202303, 202303

〔主要な業績〕Observation of spin signal in molecular nanojunctions utilizing magnetic thin-film edges at room temperature　　　　　　　　　　　　　　　
M. Matsuzaka1; Y. Sasaki; K. Hayashi; T. Misawa; T. Komine; T. Akutagawa; M. Fujioka; J. Nishii; H. Kaiju
The 23rd RIES-Hokudai International Symposium, 2022年12月
202212, 202212

〔主要な業績〕Room-temperature magnetoresistance in Ni₇₈Fe₂₂/C8-BTBT/Ni₇₈Fe₂₂ nanojunctions fabricated using magnetic thin-film edges　　　　　　　　　　　　　　　
M. Matsuzaka; Y. Sasaki; K. Hayashi; T. Misawa; T. Komine; T. Akutagawa; M. Fujioka; J. Nishii; H. Kaiju
MNC 2022, 35th International Microprocesses and Nanotechnology Conference, 2022年11月
202211, 202211

〔主要な業績〕Combination dependence of printing characteristics in double magnet master media for energy-assisted magnetic recording　　　　　　　　　　　　　　　
T. Komine
The 67th Annual Magnetism and Magnetic Materials (MMM) Conference, 2022年11月
202210, 202211

〔主要な業績〕Observation of magnetoresistance in Ni₇₈Fe₂₂/C8-BTBT/Ni₇₈Fe₂₂ nanojunctions at room temperature　　　　　　　　　　　　　　　
M. Matsuzaka; Y. Sasaki; K. Hayashi; T. Misawa; T. Komine; T. Akutagawa; M. Fujioka; J. Nishii; H. Kaiju
第83回 応用物理学会秋季学術講演会, 2022年09月
202209, 202209

〔主要な業績〕Type-II Na-Siクラスレートにおける Naイオンの拡散機構解明　　　　　　　　　　　　　　　
岩﨑秀,小峰啓史,森田一軌,澁谷泰蔵,森戸春彦,藤岡正弥
金属学会2022年秋期講演大会, 2022年09月
202209, 202209

マイクロマグネティックス(微細領域の磁性とデバイス応用)　　　　　　　　　　　　　　　
小峰啓史
第45回日本磁気学会サマースクール, 2022年06月, 日本磁気学会, ［招待有り］
202206, 202207

マイクロマグネティックス(微細領域の磁性とデバイス応用)　　　　　　　　　　　　　　　
小峰啓史
第46回日本磁気学会サマースクール, 2023年05月, 日本磁気学会, ［招待有り］
202205, 202206

〔主要な業績〕Naイオンの異方的拡散制御による Si 同素体のバルク単結晶開発　　　　　　　　　　　　　　　
藤岡 正弥,岩崎 秀,西井 準治,森戸春彦,小峰 啓史
日本セラミックス協会, 2022年03月
202203, 202203

〔主要な業績〕Voltage-control of magnetic properties in topological-insulator/magnetic-insulator bilayers　　　　　　　　　　　　　　　
T. Chiba; A. O. Leon; T. Komine
2022 Joint MMM-Intermag Conference, 2022年01月, ［招待有り］
202201, 202201

〔主要な業績〕Master structure dependence of double magnet master on magnetic printing performance onto energy-assisted magnetic recording　　　　　　　　　　　　　　　
T. Komine
2022 Joint MMM-Intermag Conference, 2022年01月
202201, 202201

トポロジカル絶縁体を活用した磁化ダイナミクスの電圧制御とその応用　　　　　　　　　　　　　　　
千葉貴裕,アレハンドロ・レオン,小峰啓史
第240回研究会／第95回ナノマグネティックス専門研究会 「磁気物性に関する計算科学の最前線」, 2022年12月
202112, 202112

Voltage-driven magnetization switching in topological-insulator-based magnetic heterostructures　　　　　　　　　　　　　　　
T. Chiba; Alejandro O. Leon; T. Komine
Joint Conference: 24th International Conference on Electronic Properties of Two-Dimensional Systems / 20th International Conference on Modulated Semiconductor Structures (EP2Ds-24/MSS-20), 2021年10月
202110, 202111

磁気を利用した熱電変換素子　　　　　　　　　　　　　　　
小峰啓史
JST新技術説明会【先端ものづくり技術】, 2021年09月, ［招待有り］
202109, 202109

トポロジカル絶縁体/磁性絶縁体二層膜における磁気特性の電圧制御　　　　　　　　　　　　　　　
千葉貴裕,Alejandro O. Leon,小峰啓史
第45回日本磁気学会学術講演会, 2021年08月
202108, 202109

ダブルマグネット型マスター媒体による磁気転写特性のマスター構造依存性　　　　　　　　　　　　　　　
小峰啓史
第45回日本磁気学会学術講演会, 2021年08月
202108, 202109

〔主要な業績〕Double magnet master media for magnetic printing onto energy-assisted magnetic recording media　　　　　　　　　　　　　　　
T. Komine
INTERMAG 2021, 2021年04月
202104, 202106

マイクロマグネティックス(微細領域の磁性とデバイス応用)　　　　　　　　　　　　　　　
小峰啓史
第44回日本磁気学会サマースクール, 2021年06月, 日本磁気学会, ［招待有り］
202106, 202106

マイクロマグネティックス(微細領域の磁性とデバイス応用)　　　　　　　　　　　　　　　
小峰啓史
第43回日本磁気学会サマースクール, 2020年12月, 日本磁気学会, ［招待有り］
202012, 202012

磁性トポロジカル絶縁体の非対称表面を利用した両極性伝導型熱電素子　　　　　　　　　　　　　　　
千葉貴裕,小峰啓史,高橋三郎
第67回 応用物理学会春季学術講演会, 2020年03月

トポロジカル絶縁体Bi_2−xSb_xTe_3−ySe_y表面の熱電特性:イオン不純物の影響　　　　　　　　　　　　　　　
千葉貴裕,小峰啓史,高橋三郎
第67回 応用物理学会春季学術講演会, 2020年03月

Ni₇₈Fe₂₂/Mq₃ (M=Al, Er)/Ni₇₈Fe₂₂ nanoscale junction devices utilizing magnetic thin-film edges　　　　　　　　　　　　　　　
Y. Sasaki; R. Msiska; T. Misawa; S. Mori; T. Komine; N. Hoshino; T. Akutagawa; M. Fujioka; J. Nishii; H. Kaiju
The 3rd workshop on functional materials science, 2019年12月

Electric and magnetic properties in Ni₇₈Fe₂₂/Mq₃(M=Al, Er)/Ni₇₈Fe₂₂ nanoscale junction devices utilizing magnetic thin-film edges　　　　　　　　　　　　　　　
The 13th Pacific Rim Conference of Ceramic Societies(PACRIM13), 2019年10月

Bi ナノワイヤーにおける格子圧縮が輸送特性に及ぼす影響　　　　　　　　　　　　　　　
小峰啓史,青野友祐,村田正行,長谷川靖洋
第80回 応用物理学会秋季学術講演会, 2019年09月

直径400nm級Biナノワイヤーの熱・電流磁気効果　　　　　　　　　　　　　　　
村田正行,冨岡平祐,青山佳代,山本淳,長谷川靖洋,小峰啓史
第80回 応用物理学会秋季学術講演会, 2019年09月

石英ガラステンプレートを用いたBi ナノワイヤーの作製と熱電物性評価　　　　　　　　　　　　　　　
小峰啓史,村田正行,長谷川靖洋
第165回 日本金属学会秋期講演大会, 2019年09月, ［招待有り］

First principle band calculations of Mg₂Si thin films　　　　　　　　　　　　　　　
M. Takizawa; T. Komine; H. Udono; T. Aono
APAC SILICIDE 2019(The 5th Asia-Pacific Conference on Semiconductor Silicides and Related Materials), 2019年07月

積層構造磁性体ナノワイヤにおける電流誘起磁壁移動　　　　　　　　　　　　　　　
小峰
電子情報通信学会，映像メディア学会 マルチメディアストレージ研究会，, 磁気記録・情報ストレージ研究会 共催(MMS, IEICE-MRIS), 2019年06月

スパッタリングで形成したTa薄膜における電気抵抗の歪み誘起1/f 雑音　　　　　　　　　　　　　　　
上杉良太,小峰啓史,水野将臣,安藤亮,赤羽秀郎
第66回 応用物理学会春季学術講演会, 2019年03月

Biナノワイヤーにおける格子圧縮が量子効果に及ぼす影響　　　　　　　　　　　　　　　
小峰啓史,青野友祐,村田正行,長谷川靖洋
第66回 応用物理学会春季学術講演会, 2019年03月

TbFeCo 磁性薄膜における輸送特性の組成依存性　　　　　　　　　　　　　　　
安藤亮,小峰啓史
第66回 応用物理学会春季学術講演会, 2019年03月

Voltage-induced Magnetocapacitance in Magnetic Tunnel Junctions　　　　　　　　　　　　　　　
H. Kaiju; T. Misawa; T. Nagahama; T. Komine; O. Kitakami; M. Fujioka; J. Nishii; G. Xiao
2019 Joint MMM-Intermag Conference, 2019年01月, MMM

Electric and magnetic properties of Ni₇₈Fe₂₂/Alq₃/Ni₇₈Fe₂₂ nanoscale junction devices utilizing magnetic thin-film edges　　　　　　　　　　　　　　　
Y. Sasaki; R. Msiska; T. Misawa; S. Mori; T. Komine; N. Hoshino; T. Akutagawa; M. Fujioka; J. Nishii; H. Kaiju
2019 Joint MMM-Intermag Conference, 2019年01月, MMM

磁性薄膜エッジを利用したNi₇₈Fe₂₂/Alq₃/Ni₇₈Fe₂₂ナノ接合素子の電気磁気特性　　　　　　　　　　　　　　　
佐々木悠馬; ムシスカロビン; 三澤貴浩; 森澄人; 小峰啓史; 星野哲久; 芥川智行; 藤岡正弥; 西井準治; 海住英生
第79回 応用物理学会秋季学術講演会, 2018年09月

Transport measurements of bismuth nanowire embedded in quartz template by nano-fabrication　　　　　　　　　　　　　　　
Y. Hasegawa; H. Morita; M. Otsuka; T. Arisaka; T. Komine
37th annual international conference on thermoelectrics (ICT), 2018年07月

面内磁場下の量子ポイントコンタクトにおける動的核スピン偏極　　　　　　　　　　　　　　　
青野友祐,Peter Stano,川村稔,大野圭司,小峰啓史
日本物理学会 第73回年次大会(2018年), 2018年03月

磁性薄膜における電極配置が異常ネルンスト起電力に及ぼす影響　　　　　　　　　　　　　　　
安藤亮,小峰啓史
第65回 応用物理学会春季学術講演会, 2018年03月

磁性薄膜エッジを利用したNi₇₈Fe₂₂/Alq₃/Ni₇₈Fe₂₂ナノ接合素子に関する研究　　　　　　　　　　　　　　　
佐々木悠馬,三澤貴浩,森澄人,小峰啓史,星野哲久,芥川智行,藤岡正弥,西井準治,海住英生
第５３回応用物理学会北海道支部/第１４回日本光学会北海道支部合同学術講演会, 2018年01月

Study of Ni₇₈Fe₂₂/Alq₃/Ni₇₈Fe₂₂ nanoscale junction devices utilizing thin-film edges　　　　　　　　　　　　　　　
Y. Sasaki; T. Misawa; S. Mori; T. Komine; N. Hoshino; T. Akutagawa; M. Fujioka; J. Nishii; H. Kaiju
The 18th RIES-HOKUDAI International Symposium, 2017年12月

Novel behaviors of anomalous Hall effect in TbFeCo thin films under high magnetic field　　　　　　　　　　　　　　　
R. Ando; T. Komine; S. Sato; S. Kaneta; Y. Hara
62nd Annual Magnetism and Magnetic Materials (MMM) Conference, 2017年11月, MMM

Geometrical contribution to anomalous Nernst effect in TbFeCo thin films　　　　　　　　　　　　　　　
R. Ando; T. Komine
62nd Annual Magnetism and Magnetic Materials (MMM) Conference, 2017年11月, MMM

Ni₇₈Fe₂₂/Alq₃/Ni₇₈Fe₂₂ナノ接合素子の電気伝導特性　　　　　　　　　　　　　　　
三澤貴浩,森澄人,佐々木悠馬,小峰啓史,星野哲久,芥川智行, 藤岡正弥,西井準治,海住英生
第78回 応用物理学会秋季学術講演会, 2017年09月

フェリ磁性TbFeCoにおける熱電効果の素子形状依存性　　　　　　　　　　　　　　　
安藤亮,小峰啓史
第78回 応用物理学会秋季学術講演会, 2017年09月

Ni₇₈Fe₂₂/Alq₃/Ni₇₈Fe₂₂接合素子における量子・古典状態間遷移領域に関する研究　　　　　　　　　　　　　　　
佐々木悠馬,三澤貴浩,森澄人,小峰啓史,星野哲久,芥川智行,藤岡正弥,西井準治,海住英生
第78回 応用物理学会秋季学術講演会, 2017年09月

Macroscale thermoelectric materials with low dimensional nanoscale features　　　　　　　　　　　　　　　
T. Ikeda; M. Murata; T. Komine; H. Kiue; Y. Hasegawa
36th annual international conference on thermoelectrics (ICT), 2017年08月

"磁場中の量子ポイントコンタクトにおける電子状態と電気伝導 II　　　　　　　　　　　　　　　
青野友祐,川村稔,大野圭司,Peter Stano,小峰啓史
日本物理学会 第72回年次大会, 2017年03月

ビスマスの格子変形がバンド構造および輸送特性に及ぼす影響　　　　　　　　　　　　　　　
小峰啓史,青野友祐,村田正行,長谷川靖洋
第64回 応用物理学会春季学術講演会, 2017年03月

フェリ磁性TbFeCo 薄膜における異常ホール効果の膜厚依存性　　　　　　　　　　　　　　　
安藤亮,小峰啓史,佐藤汐莉,金田真悟,原嘉昭
第64回 応用物理学会春季学術講演会, 2017年03月

積層型磁性ナノワイヤにおける電流誘起磁壁移動　　　　　　　　　　　　　　　
小峰啓史
第32回日本磁気学会光機能磁性デバイス・材料専門研究会/ 第32回光機能磁性デバイス・材料専門研究会, 2017年03月, ［招待有り］

Influence Of Structural Inversion Asymmetry On Current-induced Domain Wall Motion In Bilayer Nanowires With Ferro- and Antiferromagnetic Coupling　　　　　　　　　　　　　　　
T. Komine; T. Aono
61th Annual Magnetism and Magnetic Materials (MMM) Conference, 2016年11月, MMM

積層型磁性ナノワイヤにおける電流誘起磁壁移動　　　　　　　　　　　　　　　
小峰啓史
北海道大学電子科学研究所学術講演会, 2016年09月, 北海道大学電子科学研究所学術交流委員会，応用物理学会北海道支部・エンレイソウの会, ［招待有り］

薄膜エッジを利用したNi₇₈Fe₂₂/Alq₃/Ni₇₈Fe₂₂ナノ接合の作製とその構造・電気伝導特性　　　　　　　　　　　　　　　
三澤貴浩,森澄人,小峰啓史,星野哲久,芥川智行,藤岡正弥,海住英生,西井準治
第77回 応用物理学会秋季学術講演会, 2016年09月

石英ガラス中の直径110 nm Biナノワイヤーへの端部電極形成　　　　　　　　　　　　　　　
村田正行,山本淳,長谷川靖洋,小峰啓史
第77回 応用物理学会秋季学術講演会, 2016年09月

ビスマスの格子変形が輸送特性に及ぼす影響　　　　　　　　　　　　　　　
小峰啓史,青野友祐,村田正行,長谷川靖洋
第77回 応用物理学会秋季学術講演会, 2016年09月

フェリ磁性TbFeCo薄膜における異常ホール効果の強磁場特性　　　　　　　　　　　　　　　
小峰啓史,安藤亮,金田真悟,佐藤汐莉,原嘉昭
第77回 応用物理学会秋季学術講演会, 2016年09月

直径 110 nm Biナノワイヤーの熱電物性測定　　　　　　　　　　　　　　　
村田正行,山本淳,長谷川靖洋,小峰啓史
第十三回日本熱電学会学術講演会（TSJ2016）, 2016年09月

Numerical analysis of surface states in Bi nanostructure　　　　　　　　　　　　　　　
T. Komine; T. Aono; M. Murata; Y. Hasegawa
35th annual international conference on thermoelectrics & 1st asian conference on thermoelectrics (ICT & ACT 2016), 2016年06月

Nano-scale electrical contact onto 110 nm Bi nanowire encapsulated in quartz template utilizing FIB-SEM　　　　　　　　　　　　　　　
M. Murata; A. Yamamoto; Y. Hasegawa; T. Komine
35th annual international conference on thermoelectrics & 1st asian conference on thermoelectrics (ICT & ACT 2016), 2016年06月

Biナノワイヤーの磁場中における電気物性の解析　　　　　　　　　　　　　　　
村田正行,山本淳,長谷川靖洋,小峰啓史
2016年第63回応用物理学会春季学術講演会, 2016年03月

ディラック電子中の量子ドットによる熱電特性の解析　　　　　　　　　　　　　　　
青野友祐,小峰啓史
日本物理学会第71回年次大会2016, 2016年03月

積層構造ナノワイヤにおける電流誘起磁壁移動の数値解析　　　　　　　　　　　　　　　
小峰啓史,青野友祐,安藤亮
2016年第63回応用物理学会春季学術講演会, 2016年03月

漏洩磁場を利用したスピン量子十字デバイスの構造・磁気特性　　　　　　　　　　　　　　　
海住英生,森澄人,三澤貴浩,小峰啓史,中村晃輔,藤岡正弥,西井準治
2016年第63回応用物理学会春季学術講演会, 2016年03月

ビスマスナノ構造における表面状態の数値解析　　　　　　　　　　　　　　　
青野友祐,小峰啓史,村田正行,長谷川靖洋
2016年第63回応用物理学会春季学術講演会, 2016年03月

Micromagnetic analysis of current-induced domain wall motion in a bilayer nanowire with synthetic antiferromagnetic coupling　　　　　　　　　　　　　　　
T. Komine; T. Aono
2016 Joint MMM-Intermag Conference, 2016年01月

積層型ナノワイヤにおける層間交換結合が電流誘起磁壁移動に及ぼす影響　　　　　　　　　　　　　　　
小峰啓史,青野友佑
第76回 応用物理学会秋季学術講演会, 2015年09月

バンド構造の温度依存性を考慮したBi-Sb合金の熱電物性の解析　　　　　　　　　　　　　　　
村田正行,山本淳,長谷川靖洋,小峰啓史
第十二回日本熱電学会学術講演会（TSJ2015）, 2015年09月

Numerical analysis of surface spin states on bismuth thin films　　　　　　　　　　　　　　　
K. Saito; H. Sawahata; T. Komine; T. Aono
21st International Conference on Electronic Properties of Two-Dimensional Systems (EP2DS) & 17th International Conference on Modulated Semiconductor Structures(MSS), 2015年07月

Magnetic field dependences of thermoelectric properties of a sintered Bi₉₀Sb₁₀ alloy　　　　　　　　　　　　　　　
M. Murata; A. Yamamoto; Y. Hasegawa; T. Komine
The 34th International & 13th European Conference on Thermoelectrics (ICT&ECT), 2015年06月

Anomalous Nernst effect of perpendicularly magnetic anisotropy TbFeCo Thin films　　　　　　　　　　　　　　　
R. Ando; T. Komine; Y. Hasegawa
The 34th International & 13th European Conference on Thermoelectrics (ICT&ECT), 2015年06月

Enhancement of Seebeck coefficient in Bi nanowires by electric field effect　　　　　　　　　　　　　　　
T. Komine; T. Aono; Y. Nabatame; M. Murata; Y. Hasegawa
The 34th International & 13th European Conference on Thermoelectrics (ICT&ECT), 2015年06月

ビスマス薄膜表面におけるスピン分極の数値解析　　　　　　　　　　　　　　　
齊藤和雄,青野友祐,小峰啓史
日本物理学会 第70回年次大会（2015年）, 2015年03月

焼結法により作製したBi-Sb合金の磁場中の熱電物性　　　　　　　　　　　　　　　
村田正行,山本淳,長谷川靖洋,小峰啓史
2015年 第62回応用物理学会春季学術講演会, 2015年03月

バルク熱電材料のゼーベック係数・抵抗率・熱拡散率の同時測定　　　　　　　　　　　　　　　
本間亮英,寺門宏樹,長谷川靖洋,村田正行,山本淳,小峰啓史,森田寛之
2015年 第62回応用物理学会春季学術講演会, 2015年03月

補償組成近傍TbFeCo垂直磁気異方性薄膜の異常ネルンスト効果　　　　　　　　　　　　　　　
安藤亮,加藤健,飯村修志,小峰啓史,長谷川靖洋
2015年 第62回応用物理学会春季学術講演会, 2015年03月

Fabrication and Thermoelectric Properties of Individual and Single-Crystal Bismuth Nanowires Encapsulated in Quartz Templates　　　　　　　　　　　　　　　
M. Murata; H. Terakado; R. Honma; A. Yamamoto; Y. Hasegawa; T. Komine
MRS, 2014年12月

ビスマス薄膜の表面電子状態の数値計算　　　　　　　　　　　　　　　
齊藤和雄,青野友祐,小峰啓史
平成26年度（第22回）電気学会東京支部茨城支所研究発表会, 2014年11月

Influence of eddy current on current-induced domain wall motion in a magnetic nanowire　　　　　　　　　　　　　　　
T. Komine; T. Aono; R. Ando
59th Annual Magnetism and Magnetic Materials Conference(MMM), 2014年11月, MMM

Structural and Magnetic Properties of Co-based Spin Quantum Cross Devices Utilizing Stray Magnetic Fields　　　　　　　　　　　　　　　
H. Kaiju; H. Kasa; T. Komine; T. Abe; S. Mori; T. Misawa; J. Nishii
59th Annual Magnetism and Magnetic Materials Conference(MMM), 2014年11月, MMM

First principle study of magnetocrystalline anisotropy in hcp Co with stacking faults　　　　　　　　　　　　　　　
T. Komine; S. Saito
59th Annual Magnetism and Magnetic Materials Conference(MMM), 2014年11月, MMM

石英ガラスを利用したBi ナノワイヤーの作製と熱電物性の評価　　　　　　　　　　　　　　　
村田正行,山本淳,長谷川靖洋,小峰啓史
日本機械学会第６回マイクロ・ナノ工学シンポジウム, 2014年10月

Bi-Sb系バルク材料の熱伝導率評価　　　　　　　　　　　　　　　
村田正行,山本淳,本間亮英,寺門宏樹,長谷川靖洋,小峰啓史
第十一回日本熱電学会学術講演会 (TSJ2014), 2014年09月, 日本熱電学会

バルク熱電材料の熱拡散率とゼーベック係数の同時測定法の開発　　　　　　　　　　　　　　　
本間亮英,寺門宏樹,長谷川靖洋,小峰啓史,森田寛之
第十一回日本熱電学会学術講演会 (TSJ2014), 2014年09月, 日本熱電学会

引き伸ばし法を用いて作製したBiマイクロ/ナノワイヤーの熱電物性の直径依存性　　　　　　　　　　　　　　　
寺門宏樹,本間亮英,長谷川靖洋,小峰啓史,森田寛之,山嵜正明,寺嶋徹
第十一回日本熱電学会学術講演会 (TSJ2014), 2014年09月, 日本熱電学会

3ω法によるワイヤー系熱電材料の熱伝導率評価　　　　　　　　　　　　　　　
森田寛之,寺門宏樹,本間亮英,長谷川靖洋,小峰啓史
第十一回日本熱電学会学術講演会 (TSJ2014), 2014年09月, 日本熱電学会

鋳型圧入法によるBiナノワイヤーの開発と熱電物性の評価　　　　　　　　　　　　　　　
村田正行,山本淳,寺門宏樹,本間亮英,長谷川靖洋,小峰啓史
2014年 第75回応用物理学会秋季学術講演会, 2014年09月, 応用物理学会

Bi-Sb系バルク材料の作製と熱電物性の評価　　　　　　　　　　　　　　　
村田正行,山本淳,長谷川靖洋,小峰啓史
2014年 第75回応用物理学会秋季学術講演会, 2014年09月, 応用物理学会

直径700nm Biナノワイヤーのホール係数測定とキャリア移動度評価　　　　　　　　　　　　　　　
村田正行,山本淳,長谷川靖洋,小峰啓史
2014年 第75回応用物理学会秋季学術講演会, 2014年09月, 応用物理学会

漏洩磁場を用いたスピン量子十字デバイスの磁気特性　　　　　　　　　　　　　　　
森澄人,三澤貴浩,笠晴也,小峰啓史,阿部太郎,海住英生,西井準治
2014年 第75回応用物理学会秋季学術講演会, 2014年09月

積層欠陥を含むhcp Co の磁気異方性に関する第一原理計算　　　　　　　　　　　　　　　
小峰啓史,齊藤伸
第38回 日本磁気学会学術講演会, 2014年09月, 日本磁気学会

Spin quantum cross devices utilizing stray magnetic field　　　　　　　　　　　　　　　
S. Mori; T. Misawa; H. Kasa; T. Komine; T. Abe; H. Kaiju; J. Nishii
The 1st Korea-Japan Bilateral Workshop on Functional Materials Science Thermoelectrics, Spintronics, Low-dimensional Materials, and Soft Matter-, 2014年08月

Magnetic Properties of Spin Quantum Cross Devices Utilizing Stray Magnetic Fields　　　　　　　　　　　　　　　
H. Kaiju; H. Kasa; T. Komine; T. Abe; T. Misawa; J. Nishii
2014 MRS Spring Meeting & Exhibit, 2014年04月, MRS

熱電対からの熱流出に伴うゼーベック係数測定の誤差評価　　　　　　　　　　　　　　　
本間亮英,村田正行,寺門宏樹,長谷川靖洋,小峰啓史
2014年第61回応用物理学会春季学術講演会, 2014年03月

Biナノワイヤーの結晶方向が輸送特性に及ぼす影響　　　　　　　　　　　　　　　
内田仁志,青天目悠太,小峰啓史,青野友祐,村田正行,長谷川靖洋
2014年第61回応用物理学会春季学術講演会, 2014年03月

引き伸ばし法を用いて作製したBiワイヤーの熱電特性評価　　　　　　　　　　　　　　　
寺門宏樹,村田正行,本間亮英,長谷川靖洋,小峰啓史,山嵜正明,寺嶋徹
2014年第61回応用物理学会春季学術講演会, 2014年03月

補償組成近傍TbFeCo薄膜のスピン分極率　　　　　　　　　　　　　　　
伊藤,小峰,杉田,上野,山口,Bang Do,粟野
第37回日本磁気学会学術講演会, 2013年09月

Magnetostatic interaction between continuous and granular layers in multilayered nanowires for current-induced domain wall motion　　　　　　　　　　　　　　　
A. Ooba; T. Komine; R. Sugita
Joint European Magnetic Symposia (JEMS), 2012年09月

Magnetic domain structure in thin CoPt perpendicular magnetic anisotropy films　　　　　　　　　　　　　　　
Y. Kawada; M. Onose; R. Tojo; T. Komine; R. Sugita
Joint European Magnetic Symposia (JEMS), 2012年09月

Magnetization reversal process in ECC media　　　　　　　　　　　　　　　
A. Oyama; T. Komine; R. Sugita
Joint European Magnetic Symposia (JEMS), 2012年09月

Biナノワイヤー熱電変換素子の抵抗率の温度依存性　　　　　　　　　　　　　　　
村田,常見,齋藤,代田,藤原,長谷川,小峰
日本熱電学会, 2012年08月

Numerical analysis of transport properties in BiSb nanowires　　　　　　　　　　　　　　　
Y. Nabatame; T. Matsumoto; Y. Ichige; T. Komine; R. Sugita; M. Murata; Y. Hasegawa
The 31st International & 10th European Conference on Thermoelectrics (ICT&ECT), 2012年07月

Numerical analysis of transport properties in BiSb nanowires　　　　　　　　　　　　　　　
M. Murata; T. Tsunemi; Y. Hasegawa; T. Komine
The 31st International & 10th European Conference on Thermoelectrics (ICT&ECT), 2012年07月

Influence of interlayer coupling on domain wall motion in multilayered nanowires for achieving high density bit　　　　　　　　　　　　　　　
A. Ooba; T. Komine; R. Sugita
International Magnetics Conference INTERMAG 2012, 2012年05月

Effect of applied magnetic field direction on magnetic cluster state of perpendicular recording media　　　　　　　　　　　　　　　
S. Sato; Y. Yamaguchi; T. Komine; R. Sugita
International Magnetics Conference INTERMAG 2012, 2012年05月

石英ガラス中のBiナノワイヤー上へのホール測定用局所電極の形成　　　　　　　　　　　　　　　
村田,山本,常見,長谷川,小峰
2012年春季 第58回応用物理学関係連合講演会, 2012年03月

スペーシングが磁気転写特性に及ぼす影響　　　　　　　　　　　　　　　
大山,小野瀬,川崎,小峰,杉田
電気学会東京支部茨城支所発表会, 2011年11月

磁壁ピン止めを有すナノワイヤにおける電流誘起磁壁移動のシミュレーション　　　　　　　　　　　　　　　
岩井,大庭,小峰,杉田
電気学会東京支部茨城支所発表会, 2011年11月

Biワイヤーの熱電特性及びその磁場効果　　　　　　　　　　　　　　　
小峰,長谷川
磁気学会スピンエレクトロニクス専門研究会・ 応用物理学会スピントロニクス研究会(共催), 2011年11月, ［招待有り］

Current-induced domain wall motion in a multilayered nanowire for achieving high density bit　　　　　　　　　　　　　　　
T. Komine; A. Ooba; R. Sugita
56th Conference on Magnetism and Magnetic Materials(MMM), 2011年11月

積層構造垂直磁気異方性マスター媒体による垂直磁気転写　　　　　　　　　　　　　　　
川崎,小野瀬,小峰,杉田
第35回日本磁気学会学術講演会, 2011年09月

クロストラック方向における磁気転写特性　　　　　　　　　　　　　　　
川前,小峰,杉田
第35回日本磁気学会学術講演会, 2011年09月

スペーシングが磁気転写特性に及ぼす影響　　　　　　　　　　　　　　　
小野瀬,川崎,小峰,杉田
第35回日本磁気学会学術講演会, 2011年09月

ECC 媒体における磁気クラスタサイズの磁場印加方向依存性　　　　　　　　　　　　　　　
山口,川田,小峰,杉田
第35回日本磁気学会学術講演会, 2011年09月

CoPt垂直磁気異方性膜の磁気特性の膜厚依存性　　　　　　　　　　　　　　　
川田,小野瀬,川崎,大山,小峰,杉田
第35回日本磁気学会学術講演会, 2011年09月

磁壁ピン止めを有するナノワイヤにおける電流誘起磁壁移動のシミュレーション　　　　　　　　　　　　　　　
大庭,藤村,小峰,杉田
第35回日本磁気学会学術講演会, 2011年09月

集束イオンビーム加工を利用したBiナノワイヤー熱電変換素子の4端子測定　　　　　　　　　　　　　　　
村田,山本,常見,長谷川,小峰
日本熱電学会, 2011年08月

Fourwire resistance measurements on bismuth nanowire encased in quartz template utilizing focused ion beam processing　　　　　　　　　　　　　　　
M. Murata; H. Yamamoto; F. Tsunemi; Y. Hasegawa; T. Komine
30th International Conference on Thermoelectrics, 2011年07月

Effect of the pinning field on critical current density for current-induced domain wall motion in perpendicular magnetic anisotropy nanowires　　　　　　　　　　　　　　　
A. Ooba; Y. Fujimura; K. Takahashi; T. Komine; R. Sugita
Recent Trends in Nanomagnetism, Spintronics and their Applications, 2011年06月

Micromagnetic study for effect of applied magnetic field direction on magnetic cluster size of perpendicular recording media　　　　　　　　　　　　　　　
Y. Kawada; Y. Yamaguchi; Y. Tanaka; T. Kawamae; T. Komine; R. Sugita
International Magnetics Conference INTERMAG 2011, 2011年04月

Magnetization distribution of Tb/in² class hard disks recorded with bit printing and edge printing　　　　　　　　　　　　　　　
T. Murakoshi; T. Komine; R. Sugita
International Magnetics Conference INTERMAG 2011, 2011年04月

ビスマス微細構造における電子状態　　　　　　　　　　　　　　　
澤畠,小峰,青野
2011年春季 第57回応用物理学関係連合講演会, 2011年03月

表面ポテンシャルがBiナノワイヤーの輸送特性に及ぼす影響　　　　　　　　　　　　　　　
青天目,松本,市毛,小峰,杉田, 青野,村田,中村,長谷川
2011年春季 第57回応用物理学関係連合講演会, 2011年03月

無冷媒冷凍機を用いた熱電物性測定装置の温度制御法　　　　　　　　　　　　　　　
常見,中村,村田,山本,長谷川,小峰
2011年春季 第57回応用物理学関係連合講演会, 2011年03月

熱リークを制御した定常法による熱伝導測定システムの構築　　　　　　　　　　　　　　　
山本,中村,村田,常見,長谷川,小峰
2011年春季 第57回応用物理学関係連合講演会, 2011年03月

収束イオンビーム加工を利用した Bi ナノワイヤーの4端子測定　　　　　　　　　　　　　　　
村田,中村,山本,常見,長谷川,小峰
2011年春季 第57回応用物理学関係連合講演会, 2011年03月

直径 725 nm Bi ナノワイヤーの熱電特性測定及び解析　　　　　　　　　　　　　　　
中村,村田,山本,常見,長谷川,小峰
2011年春季 第57回応用物理学関係連合講演会, 2011年03月

GM冷凍機における精密温度制御(2) -リアルタイム測定とその解析-　　　　　　　　　　　　　　　
中村,常見,長谷川,村田,山本,小峰
2010 年度秋季低温工学・超電導学会, 2010年12月

Reduction of intrinsic critical current density on current-induced domain wall motion by using a ferrimagnetic nanowire　　　　　　　　　　　　　　　
T. Komine; K. Takahashi; A. Ooba; R. Sugita
55th Conference on Magnetism and Magnetic Materials(MMM), Atlanta, 2010年11月

Domain-like behavior of magnetization process in magnetic checker pattern　　　　　　　　　　　　　　　
T. Komine; Y. Tanaka; R. Sugita
55th Conference on Magnetism and Magnetic Materials(MMM), Atlanta, 2010年11月

Biナノワイヤーにおける表面ポテンシャルがナノワイヤー の輸送特性に及ぼす影響　　　　　　　　　　　　　　　
青天目,市毛,松本,小峰,杉田,青野,長谷川
電気学会東京支部茨城支所発表会, 2010年11月

マスター媒体の初期磁化が磁気転写特性に及ぼす影響　　　　　　　　　　　　　　　
川田,川崎,田中,小峰,杉田
電気学会東京支部茨城支所発表会, 2010年11月

垂直磁気異方性細線における電流誘起磁壁移動のマイクロ マグネティックシミュレーション　　　　　　　　　　　　　　　
大庭,高橋,小峰,杉田
電気学会東京支部茨城支所発表会, 2010年11月

ビスマス微細構造における電子状態　　　　　　　　　　　　　　　
澤畠,小峰,青野
電気学会東京支部茨城支所発表会, 2010年11月

垂直磁気異方性を有する磁性細線における電流誘起磁壁移動のマイクロマグネティックシミュレーション　　　　　　　　　　　　　　　
小峰
スピニクス特別研究会, 2010年10月, ［招待有り］

マスターパターンサイズが磁気転写特性に及ぼす影響　　　　　　　　　　　　　　　
川前,小峰,杉田
日本磁気学会学術講演会, 2010年09月

マスター媒体の初期磁化が磁気転写特性に及ぼす影響　　　　　　　　　　　　　　　
川崎,田中,小峰,杉田
日本磁気学会学術講演会, 2010年09月

垂直磁気異方性マスター媒体の磁区が 磁気転写特性に及ぼす影響　　　　　　　　　　　　　　　
田中,小峰,杉田
日本磁気学会学術講演会, 2010年09月

マスター媒体のパターン形状がビット転写特性に及ぼす影響　　　　　　　　　　　　　　　
小野瀬,川崎,川田,小峰,杉田
日本磁気学会学術講演会, 2010年09月

磁気転写及び磁気ヘッドで記録されたハードディスクの 磁化状態　　　　　　　　　　　　　　　
村越,小峰,杉田
日本磁気学会学術講演会, 2010年09月

低飽和磁化垂直磁気異方性細線における電流誘起磁壁移動の マイクロマグネティックシミュレーション　　　　　　　　　　　　　　　
高橋,大庭,村上,小峰,杉田
日本磁気学会学術講演会, 2010年09月

直径500nm級のBiナノワイヤー熱電変換素子の開発と評価　　　　　　　　　　　　　　　
村田正行,中村太紀,山本浩也,長谷川靖洋,小峰啓史
日本熱電学会, 2010年08月

熱電材料の磁場効果　　　　　　　　　　　　　　　
小峰,長谷川,中村
第173回日本磁気学会研究会, 2010年08月, ［招待有り］

ECC媒体への垂直磁気転写シミュレーション　　　　　　　　　　　　　　　
川前,村越,小峰,杉田
電子情報通信学会，映像メディア学会 磁気記録・情報ストレージ研究会, 2010年07月

CoPt垂直マスターの転写特性における組成依存性　　　　　　　　　　　　　　　
小野瀬,川崎,田中,小峰,杉田
電子情報通信学会，映像メディア学会 磁気記録・情報ストレージ研究会, 2010年07月

垂直磁気転写法によるサーボ信号記録　　　　　　　　　　　　　　　
杉田龍二,小峰啓史
電子情報通信学会，映像メディア学会 磁気記録・情報ストレージ研究会, 2010年06月

GM冷凍機における精密温度制御　　　　　　　　　　　　　　　
中村太紀,長谷川靖洋,村田正行,山本浩也,小峰啓史
2010年度春季低温工学・超電導学会, 2010年05月

Biナノワイヤーにおける輸送特性の有効質量依存性　　　　　　　　　　　　　　　
市毛雄基,松本剛,池谷政洋,小峰啓史,杉田龍二, 青野知佑,村田正行,中村太紀,長谷川靖洋
2010年春季 第56回応用物理学関係連合講演会, 2010年03月

Biナノワイヤーにおける表面ポテンシャルが ナノワイヤー輸送特性に及ぼす影響　　　　　　　　　　　　　　　
松本剛,市毛雄基,池谷政洋,小峰啓史,杉田龍二, 青野知佑,村田正行,中村太紀,長谷川靖洋
2010年春季 第56回応用物理学関係連合講演会, 2010年03月

Biナノワイヤーにおける熱電特性の結晶方向依存性　　　　　　　　　　　　　　　
村田正行,中村太紀,山本浩也,長谷川靖洋,小峰啓史
2010年春季 第56回応用物理学関係連合講演会, 2010年03月

ナノワイヤー形状での熱電材料の熱伝導率変化　　　　　　　　　　　　　　　
長谷川靖洋,村田正行,中村太紀,山本浩也,小峰啓史
2010年春季 第56回応用物理学関係連合講演会, 2010年03月

GM冷凍機の高精度温度安定法　　　　　　　　　　　　　　　
中村太紀,長谷川靖洋,村田正行,山本浩也,小峰啓史
2010年春季 第56回応用物理学関係連合講演会, 2010年03月

Influence of exchange coupling on current-driven domain wall motion in a nanowire　　　　　　　　　　　　　　　
T. Komine; K. Takahashi; H. Murakami; R. Sugita
11th Joint MMM-Intermag Conference, Washington, 2010年01月

CoPt垂直マスターの転写特性における組成依存性　　　　　　　　　　　　　　　
川崎龍太,小西弘孝,田中康貴,小峰啓史,杉田龍二
電気学会茨城支所大会, 2009年11月

UV-NIL を用いたナノパターンの作製検討　　　　　　　　　　　　　　　
松本剛,池谷政洋,市毛雄基,高橋光太,東川玲子,櫻井淳光,小峰啓史,杉田龍二
電気学会茨城支所大会, 2009年11月

磁性細線における磁壁移動の電流パルス依存性　　　　　　　　　　　　　　　
小峰啓史,村上宏,杉田龍二
電子情報通信学会，映像メディア学会 磁気記録・情報ストレージ研究会, 2009年10月

磁性細線における磁壁移動の交換スティフネス定数依存性　　　　　　　　　　　　　　　
高橋,村上,小峰,杉田
日本磁気学会学術講演会, 2009年09月

垂直磁気異方性ナノワイヤにおけるマルチビットの磁壁移動　　　　　　　　　　　　　　　
村上,高橋,小峰,杉田
日本磁気学会学術講演会, 2009年09月

CoPt垂直マスターの転写特性における組成依存性　　　　　　　　　　　　　　　
小西,川崎,田中,小峰,杉田
日本磁気学会学術講演会, 2009年09月

ECC媒体への垂直磁気転写シミュレーション　　　　　　　　　　　　　　　
村越,小峰,杉田
日本磁気学会学術講演会, 2009年09月

マスターパターン形状が磁気転写特性に及ぼす影響　　　　　　　　　　　　　　　
田辺,齋藤,シダ,小峰,杉田
日本磁気学会学術講演会, 2009年09月

パターンの異なるマスターによる垂直磁気転写　　　　　　　　　　　　　　　
田中,小西,小峰,杉田
日本磁気学会学術講演会, 2009年09月

Micromagnetic study of magnetic printing onto various slave media　　　　　　　　　　　　　　　
T. Komine; T. Murakoshi; Y. Tanaka; Y. Sakaguchi; R. Sugita
International Conference on Magnetics, 2009年07月

Micromagnetic analysis of current-driven domain wall motion of multi-bit in a perpendicular magnetic anisotropy nanowire　　　　　　　　　　　　　　　
H. Murakami; T. Komine; R. Sugita
International Conference on Magnetics, 2009年07月

A technique how to contact between bismuth nano-wire edge and electrodes　　　　　　　　　　　　　　　
M. Murata; D. Nakamura; Y. Hasegawa; T. Komine; D. Uematsu; S. Nakamura; T. Taguchi
28th International Conference on Thermoelectrics, 2009年07月

Thermoelectric properties of 500nm-order individual bismuth nano-wire using quartz template　　　　　　　　　　　　　　　
D. Nakamura; M. Murata; Y. Hasegawa; T. Komine; D. Uematsu; S. Nakamura; T. Taguchi
28th International Conference on Thermoelectrics, 2009年07月

Numerical analysis of effective thermal conductivity in microwire array element　　　　　　　　　　　　　　　
T. Komine; M. Kuraishi; T. Teramoto; R. Sugita; Y. Hasegawa; M. Murata; D. Nakamura
28th International Conference on Thermoelectrics, 2009年07月

Bi ナノワイヤー熱電素子の作製法と熱電特性　　　　　　　　　　　　　　　
村田正行,中村太紀,長谷川靖洋,小峰啓史,田口隆志, 中村.真一郎, Vladimir Jovovic,Joseph P. Heremans
応用物理学会, 2009年03月

平均自由行程を考慮したBiナノワイヤーの熱電特性の解析　　　　　　　　　　　　　　　
中村太紀,村田正行,長谷川靖洋,小峰啓史,田口隆志, 中村.真一郎, Vladimir Jovovic,Joseph P. Heremans
応用物理学会, 2009年03月

UV-NILを用いたナノ構造磁性体の作製検討　　　　　　　　　　　　　　　
高橋光太,櫻井淳光,東川玲子,小峰啓史,杉田龍二, 加藤健,浅野俊之
電気学会茨城支所大会, 2008年12月

磁性細線における磁壁移動の電流パルス幅依存性　　　　　　　　　　　　　　　
村上,小峰,杉田
日本磁気学会学術講演会, 2008年09月

マスターパターンの傾きが垂直磁気転写特性に及ぼす影響　　　　　　　　　　　　　　　
齋藤,坂口,岡見,小峰,杉田
日本磁気学会学術講演会, 2008年09月

Analysis of waveforms from magnetic printed perpendicular hard disk　　　　　　　　　　　　　　　
シダ,岡見,坂口,小峰,杉田
日本磁気学会学術講演会, 2008年09月

磁性ナノクラスターにおける静磁場エネルギーのMCおよびLLGシ ミュレーション比較　　　　　　　　　　　　　　　
山口,鈴木,入戸野,小峰,高木
日本磁気学会学術講演会, 2008年09月

垂直異方性マスター媒体を用いた磁気転写の数値解析　　　　　　　　　　　　　　　
中沢,小西,シダ,在原,小峰,杉田
日本磁気学会学術講演会, 2008年09月

磁気転写及びヘッド記録された媒体からの出力波形　　　　　　　　　　　　　　　
田辺,岡見,齋藤,シダ,小峰,杉田
日本磁気学会学術講演会, 2008年09月

CoPt垂直磁気異方性膜の磁区構造　　　　　　　　　　　　　　　
小西,在原,村上,小峰,杉田
日本磁気学会学術講演会, 2008年09月

拡大モデルによる垂直磁気転写解析　　　　　　　　　　　　　　　
田邊,齋藤,Sheeda,小峰,杉田
電子情報通信学会，映像メディア学会 磁気記録・情報ストレージ研究会, 2008年07月

強磁性ナノワイヤにおける切り込みが磁壁移動に及ぼす影響　　　　　　　　　　　　　　　
村上,小峰,杉田
電子情報通信学会，映像メディア学会 磁気記録・情報ストレージ研究会, 2008年07月

A Comparison of Magnetostatic Energy between Monte Carlo and LLG Simulations for Magnetic Nano-Clusters　　　　　　　　　　　　　　　
K. Yamaguchi; K. Suzuki; O. Nittono; T. Komine; T. Takagi
CEFC2008, 2008年05月

Influence of Notch Shape and Size on Current-Driven Domain Wall Motions in a Magnetic Nanowire　　　　　　　　　　　　　　　
T. Komine; H. Murakami; T. Nagayama; R. Sugita
IEEE International Magnetics Conference 2008, 2008年05月

Feasibility of Perpendicular Magnetic Printing at 1 Tbit/inch²　　　　　　　　　　　　　　　
T. Komine; T. Murata; Y. Sakaguchi; Y. Hosoya; Nurul Sheeda Suhaimi; R. Sugita
IEEE International Magnetics Conference 2008, 2008年05月

BiSb 合金における磁気ゼーベック係数の数値解析　　　　　　　　　　　　　　　
小峰啓史,寺本貴之,杉田龍二,長谷川靖洋
応用物理学会, 2008年03月

石英中に圧入されたBi マイクロ／ナノワイヤー素子の熱電特性測定　　　　　　　　　　　　　　　
長谷川靖洋,中野博文,森田寛之,小峰啓史,田口隆志,中村真一郎
応用物理学会, 2008年03月

Ni-SiO₂グラニュラー薄膜の磁気特性　　　　　　　　　　　　　　　
櫻井淳光,石井智,飯田優,杉本太一,小峰啓史,杉田龍二
電気学会茨城支所大会, 2007年12月

高飽和磁化を有する垂直磁気異方性膜の作製　　　　　　　　　　　　　　　
在原康貴,杉田龍二,小峰啓史
電気学会茨城支所大会, 2007年12月

Analysis of Waveform from Perpendicular Magnetic Printed Media　　　　　　　　　　　　　　　
N. Sheeda; S. Okami; T. Komine; R. Sugita
9th Perpendicular Magnetic Recording Conference (PMRC), 2007年10月

1Tbit/inch²垂直磁気転写の可能性　　　　　　　　　　　　　　　
村田剛史,坂口雄一,和泉昭彦,小峰啓史,杉田龍二
日本応用磁気学会学術講演会, 2007年09月

垂直磁気転写におけるマスター磁性膜及び軟磁性裏打ち層のマ イクロマグネティックシミュレーション　　　　　　　　　　　　　　　
中澤光貴,小峰啓史,杉田龍二
日本応用磁気学会学術講演会, 2007年09月

スレーブ媒体の磁気特性が垂直磁気転写特性に及ぼす影響　　　　　　　　　　　　　　　
坂口雄一,村田剛史,小峰啓史,杉田龍二
日本応用磁気学会学術講演会, 2007年09月

位相サーボ対応垂直磁気転写の拡大モデルによる解析　　　　　　　　　　　　　　　
齊藤俊明,安田浩子,小峰啓史,杉田龍二
日本応用磁気学会学術講演会, 2007年09月

電流分布を考慮した磁壁駆動のマイクロマグネティックシミュ レーション　　　　　　　　　　　　　　　
小峰啓史,永山剛広,杉田龍二
日本応用磁気学会学術講演会, 2007年09月

蒸着テープを用いた垂直磁気転写解析　　　　　　　　　　　　　　　
NURUL SHEEDA,岡見智史,小峰啓史,杉田龍二
電子情報通信学会 磁気記録・情報ストレージ研究会, 2007年06月

Influence of Band Structure of Bi-Sb Alloy on Magneto-Seebeck Coefficient　　　　　　　　　　　　　　　
T. Teramoto; S. Yamamoto; M. Kuraishi; T. Komine; R. Sugita; Y. Hasegawa; H. Nakamura
26th International Conference On Thermoelectrics, 2007年06月

Magneto-resistivity reduction using microwire array structure element　　　　　　　　　　　　　　　
Y. Hasegawa; H. Nakano; H. Morita; T. Komine; H. Nakamura
26th International Conference on Thermoelectrics, 2007年06月

BiSb合金のバンド構造が磁気ゼーベック係数に及ぼす影響　　　　　　　　　　　　　　　
寺本貴之,山本真司,倉石正寛,小峰啓史,長谷川靖洋, 中村浩章,杉田龍二
応用物理学会, 2007年03月

磁場中におけるBiマイクロワイヤーアレイ素子のパワーファ クター評価　　　　　　　　　　　　　　　
中野博文,長谷川靖洋,神戸勇貴,森田寛之,小峰啓史
応用物理学会, 2007年03月

Biナノワイヤー熱電素子の開発　　　　　　　　　　　　　　　
長谷川靖洋,中野博文,神戸勇貴,森田寛之,小峰啓史,中村浩章
応用物理学会, 2007年03月

微小面積を持つ膜面垂直通電型抵抗素子の作製検討　　　　　　　　　　　　　　　
飯田優,石井智,杉本太一,櫻井淳光,小峰啓史,杉田龍二
電気学会茨城支所大会, 2006年12月

Influence of spacing between master and slave media on magnetic duplication characteristics for perpendicular recording media　　　　　　　　　　　　　　　
T. Murata; A. Izumi; S. Okami; N. Sheeda; T. Komine; and R. Sugita
The 8th Asian Symposium on Information Storage Technology, 2006年11月

垂直磁気転写された磁化状態のマイクロマグネティック シミュレーション　　　　　　　　　　　　　　　
小峰啓史,和泉昭彦,村田剛史,杉田龍二
日本応用磁気学会学術講演会, 2006年09月

拡大モデルを用いた垂直磁気転写解析　　　　　　　　　　　　　　　
安田浩子,永利賢,鈴木麻希子,小峰啓史,杉田龍二
日本応用磁気学会学術講演会, 2006年09月

マスターの飽和磁化が垂直磁気転写特性に及ぼす影響　　　　　　　　　　　　　　　
村田剛史,和泉昭彦,小峰啓史,杉田龍二
日本応用磁気学会学術講演会, 2006年09月

垂直磁気転写特性に及ぼす軟磁性裏打ち層の影響　　　　　　　　　　　　　　　
和泉昭彦,村田剛史,小峰啓史,杉田龍二
日本応用磁気学会学術講演会, 2006年09月

磁気転写技術の高密度記録性能　　　　　　　　　　　　　　　
若松哲史,西川正一,市川健次,宇佐利裕,長尾 信,石岡利英, 安永正,小峰啓史,杉田龍二
日本応用磁気学会学術講演会, 2006年09月

蒸着テープを用いた垂直磁気転写解析　　　　　　　　　　　　　　　
岡見智史,丑米梨恵,小峰啓史,杉田龍二
日本応用磁気学会学術講演会, 2006年09月

Numerical analysis of effective thermal conductivity in microwire array element　　　　　　　　　　　　　　　
M. Kuraishi; T. Komine; T. Teramoto; R. Sugita; Y. Hasegawa
25th International Conference on Thermoelectrics, 2006年08月

Influence of Energy Band Structure on Thermoelectric Properties of Bismuth in the Presence of Magnetic Field　　　　　　　　　　　　　　　
T. Teramoto; T. Komine; M. Kuraishi; R. Sugita; Y. Hasegawa
25th International Conference on Thermoelectrics, 2006年08月

Geometrical dependence of magnetoresistivity in bismuth microwire arrays　　　　　　　　　　　　　　　
H. Nakano; Y. Ishikawa; Y. Hasegawa; H. Morita; T. Komine
25th International Conference on Thermoelectrics, 2006年08月

Thermoelectric property of Cu₂O thin film deposited by Reactive Ion Plating method　　　　　　　　　　　　　　　
H. Uchiyama; Y. Hasegawa; H. Morita; A. Kurokouchi; K. Wada; T. Komine
25th International Conference on Thermoelectrics, 2006年08月

斜め方向転写磁場が転写特性に及ぼす影響　　　　　　　　　　　　　　　
岡見智史,富川智史,小峰啓史,杉田龍二
電子情報通信学会 磁気記録・情報ストレージ研究会, 2006年07月

垂直磁気転写シミュレーション　　　　　　　　　　　　　　　
村田剛史,和泉昭彦,小峰啓史,杉田龍二
電子情報通信学会 磁気記録・情報ストレージ研究会, 2006年07月

面内磁気記録媒体への短ビットの磁気転写の性能と可能性　　　　　　　　　　　　　　　
長尾信,久保田秀幸,西川正一,安永正,小峰啓史,杉田龍二
電子情報通信学会 磁気記録・情報ストレージ研究会, 2006年07月

垂直磁気記録媒体へのサーボパターンの磁気転写の可能性　　　　　　　　　　　　　　　
西川正一,若松啓史,市川健次,宇佐利裕,長尾 信,石岡利英, 安永 正,小峰啓史,杉田龍二
電子情報通信学会 磁気記録・情報ストレージ研究会, 2006年07月

Influence of Soft-Under-Layer in Perpendicular Media on Magnetic Contact Duplication Characteristics　　　　　　　　　　　　　　　
A. Izumi; Y. Nagahama; T. Komine; T. Murata; R. Sugita; M. Nagao; M. Nishikawa; T.Yasunaga
International Magnetics Conference INTERMAG 2006, 2006年05月

First-Principles Calculation of atomic-sized Ni nanocontacts　　　　　　　　　　　　　　　
T. Takahashi; T. Komine; R. Sugita; Y. Hasegawa
International Magnetics Conference INTERMAG 2006, 2006年05月

Potential of Servo Pattern Printing on PMR Media With High Density Servo Signal Pattern　　　　　　　　　　　　　　　
M. Nishikawa; S. Wakamatsu; K. Ichikawa; T. Usa; M. Nagao; T. Ishioka; T.Yasunaga; T. Komine; R. Sugita
International Magnetics Conference INTERMAG 2006, 2006年05月

Biマイクロワイヤーアレイ素子の熱電特性の形状依存性　　　　　　　　　　　　　　　
中野博文,石川最朗,長谷川靖洋,森田寛之,小峰啓史
応用物理学会, 2006年03月

Cu-SiO₂グラニュラー中間層を用いたスピンバルブ 素子の磁気抵抗　　　　　　　　　　　　　　　
杉本太一,高玉晃宏,小峰啓史,杉田龍二,村野井徹夫
電気学会茨城支所大会, 2005年11月

磁気転写されたスレーブ媒体における磁化状態解析　　　　　　　　　　　　　　　
永利賢,小峰啓史,杉田龍二,村野井徹夫
電気学会茨城支所大会, 2005年11月

磁気転写特性のマスターパターン傾斜角依存性　　　　　　　　　　　　　　　
安田浩子,金子朝子,小峰啓史,杉田龍二,村野井徹夫
日本応用磁気学会, 2005年09月

基礎物理学入門　　　　　　　　　　　　　　　
2015年04月 - 2019年03月
茨城工業高等専門学校

物性物理　　　　　　　　　　　　　　　
2015年04月 - 2019年03月
茨城工業高等専門学校

基礎物理学演習　　　　　　　　　　　　　　　
2015年04月 - 2019年03月
茨城工業高等専門学校

物性工学特論　　　　　　　　　　　　　　　
2007年04月 - 2018年03月
茨城大学

電気磁気学　　　　　　　　　　　　　　　
2003年04月 - 2018年03月
茨城大学

電気電子材料　　　　　　　　　　　　　　　
2013年04月 - 2015年03月
茨城工業高等専門学校

2015年09月 - 現在, 日本熱電学会

2012年04月, IEEE

1996年04月 - 2012年03月, 金属学会

2005年04月, American Physical Society

2003年12月, 応用物理学会

1996年04月, 物理学会

1995年05月, 日本磁気学会

磁性トポロジカル絶縁体素子の界面制御による低消費電力動作の実現
基盤研究(B)
茨城大学
2024年04月01日 - 2028年03月31日

高速スクリーニングによる高効率トポロジカル熱電材料の創成　　　　　　　　　　　　　　　
2024年09月 - 2028年03月

時間軸および周波数軸を用いたTDIS法による新しい熱電材料性能評価手法の開拓　　　　　　　　　　　　　　　
挑戦的研究（萌芽）
2023年04月 - 2026年03月

1次元量子ナノワイヤー熱電変換素子の巨大ゼーベック効果の実証　　　　　　　　　　　　　　　
基盤研究(B)一般
2022年04月 - 2025年03月

量子微細構造における動的核スピン分極のコヒーレンス創発
基盤研究(C)
茨城大学
2020年04月01日 - 2024年03月31日

〔主要な業績〕磁壁移動型メモリの低消費電力動作に向けた界面構造制御　　　　　　　　　　　　　　　
基盤研究（B)
2020年04月 - 2024年03月

ナノ加工を用いた1次元量子ナノワイヤー熱電変換素子の巨大ゼーベック効果機構解明
基盤研究(B)
埼玉大学
2018年04月01日 - 2022年03月31日

ビスマスナノワイヤーにおける特異な輸送現象の解明
国際共同研究加速基金(国際共同研究強化(B))
2018年10月 - 2022年03月

電界制御ラシュバ効果による磁壁移動型メモリの高速化　　　　　　　　　　　　　　　
基盤研究(B)一般
2016年04月 - 2020年03月

ディラック電子系に対する量子ドット導入による熱電性能の増強　　　　　　　　　　　　　　　
基盤研究(C)一般
2015年04月 - 2019年03月

強磁性ナノ接合を用いた巨大磁気キャパシタンス効果素子の創製
基盤研究(B)
北海道大学
2015年04月01日 - 2018年03月31日

低次元制御量子ナノ構造をもつバルク熱電材料の創製　　　　　　　　　　　　　　　
挑戦的萌芽研究 一般
2016年04月 - 2018年03月

ナノスケール制御によるナノワイヤー熱電変換素子の巨大ゼーベック効果発現と機構解明　　　　　　　　　　　　　　　
基盤研究(B)一般
2015年04月 - 2018年03月

革新的ナノスケール制御による高効率熱電変換システムの実現　　　　　　　　　　　　　　　
2015年10月 - 2017年10月

磁気ナノ構造体における室温スキルミオンの発現とその低電流密度駆動
挑戦的萌芽研究
北海道大学
2015年04月01日 - 2017年03月31日

超高記録密度積層構造ナノワイヤメモリの低電流・高速動作に関する研究　　　　　　　　　　　　　　　
基盤研究(C)一般
2013年04月 - 2016年03月

エネルギーアシスト記録及び瓦記録方式ハードディスク対応超高速サーボ信号転写の研究　　　　　　　　　　　　　　　
基盤研究(C)一般
2012年04月 - 2015年03月

フェリ磁性積層構造を利用した高密度ナノワイヤメモリの基礎研究　　　　　　　　　　　　　　　
基盤研究(C)一般
2010年04月 - 2013年03月

収束イオンビームを用いたナノワイヤー熱電変換素子へのナノ電極形成・輸送特性の解明
基盤研究(C)
埼玉大学
2011年 - 2013年

1テラビット/平方インチ超ハードディスクへのサーボ信号記録用新磁気転写技術の開発
基盤研究(B)
茨城大学
2009年 - 2011年

スピン流分布を制御した磁壁移動型デバイス
若手研究(B)
茨城大学
2007年 - 2009年

ナノワイヤーアレイ構造を用いたバリスティック磁気抵抗素子に関する研究
若手研究(B)
茨城大学
2004年 - 2006年

パターニングされたマスター媒体を用いた高記録密度磁気転写の研究
基盤研究(C)
茨城大学
2004年 - 2006年

特許第7316579号, 特願2018-236300, 熱電変換素子,熱電変換方法
小峰啓史,安藤亮

特許第6963347号, 特開2020-35506, 特願2018-162816, 磁気パターン転写用マスター媒体及びその製造方法，磁気パターン転写方法
小峰啓史

特願2018-236300, 熱電変換素子,熱電変換方法
小峰啓史,安藤亮

USP7982984, Magnetic transfer master carrier, magnetic transfer method, and magnetic recording medium
Yoichi Nishida, Hideyuki Kubota, Masakazu Nishikawa, Makoto Nagao, Ryuji Sugita, Takashi Komine

USP7974028, Magnetic transfer master carrier and magnetic transfer method
Yoichi Nishida, Hideyuki Kubota, Makoto Nagao, Ryuji Sugita, Takashi Komine

2010-108587, 2009-221291, 磁気転写用マスター担体の製造方法、磁気転写用マスター担体、及び磁気転写方法
久保田秀幸,長尾信,杉田龍二,小峰啓史

USP0079892, Method for producing magnetic transfer master carrier, magnetic transfer master carrier and magnetic transfer method
Hideyuki Kubota, Makoto Nagao, Ryuji Sugita, Takashi Komine

2009-295250, 2008-149540, 磁気転写用マスター担体、磁気転写方法、及び磁気記録媒体
西田陽一,久保田秀幸,西川正一,長尾信,杉田龍二,小峰啓史

USP0303627, USP477350, Magnetic transfer master carrier, magnetic transfer method, and magnetic recording medium
NISHIDA, Kubota, Nishikawa, Nagao, Sugita, Komine

2009-259372, 2008-255075, 磁気転写用マスター担体、及び磁気転写方法
西田陽一,久保田秀幸,長尾信,杉田龍二,小峰啓史

2009-252341, 2008-103362, 磁気転写用マスター担体、磁気転写方法、及び垂直磁気記録媒体
諸岡篤,杉田龍二,小峰啓史

2009-252297, 2008-99621, 磁気転写用マスター担体、磁気転写方法、及び磁気記録媒体
西田陽一,久保田秀幸,西川正一,長尾信,杉田龍二,小峰啓史

2009-238288, 2008-81779, 磁気転写用マスター担体、及びその製造方法
西川正一,久保田秀幸,長尾信,杉田龍二,小峰啓史

2009-146557, 2009-146557, 2008-255719, 磁気転写用マスター担体、及びこれを用いた磁気転写方法
西田陽一,西川正一,久保田秀幸,杉田龍二,小峰啓史

EP2063421, Master carrier for magnetic transfer and magnetic recording medium manufactured using the same
Nishida Yoichi, Nishikawa Masakazu, Kubota Hideyuki, Komine Takashi, Sugita Ryuji

EPC 08253788.7 -1232, EPC 08253788.7 -1232, EPC 08253788.7 -1232, Master carrier for magnetic transfer and magnetic recording medium manufactured using the same...
Nishida, Nishikawa, Kubota, Komine, Sugita

2008-267753, 2007-95557, 磁気転写方法及び磁気記録媒体
長尾 信, 藤原 直人, 安永 正, 杉田 龍二, 小峰 啓史

EP1975929, Method of magnetic transfer and magnetic recording medium
YASUNAGA, SUGITA, FUJIWARA, NAGAO, KOMINE

2008-165884, 2006-353108, 磁気転写方法、マスター記録媒体、垂直磁気記録媒体及び磁気記録再生装置

2008-165885, 2006-353109, 磁気転写方法、磁気転写装置及び垂直磁気記録媒体
若松 哲史, 小松 和則, 安永 正, 長尾 信, 杉田 龍二, 小峰 啓史

2008-88759, 磁気転写用マスター担体，及び磁気転写方法
長尾信, 杉田龍二, 小峰啓史

US20090244747A1, MAGNETIC TRANSFER MASTER CARRIER AND METHOD FOR PRODUCING THE SAME
Nishikawa, Kubota, Nagao, Sugita, Komine

2007-302165, 磁気転写用マスター担体，及びこれを用いた磁気転写方法
長尾信, 杉田龍二, 小峰啓史

2007-97296, 磁気転写法
杉田龍二,小峰啓史,長尾信,他

特開2007-12980, 特願2005-193632, 熱電変換素子およびその製造方法
小峰啓史

特開2006-31896, 特願2004-213027, 振幅サーボパターン,磁気記録媒体およびその製造方法，その製造方法において用いられる磁気転写用パターンドマスター担体,ならびに磁気記録再生装置
小峰啓史,杉田龍二,安永正,長尾信

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