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Nobuki Tezuka

Section

Graduate School of Engineering

Job title

Professor

Degree

工学博士 (Tohoku University)

researchmap

https://researchmap.jp/read_NTezuka

J-GLOBAL ID

200901023263253645

Committee Memberships 6

日本磁気学会　現地実行委員

2007/10 - 2008/09
日本磁気学会　現地実行委員

2007/10 - 2008/09
19th International Colloquium on Magnetic Films and Surfaces現地実行委員　現地実行委員

2006/08 -
19th International Colloquium on Magnetic Films and Surfaces現地実行委員　現地実行委員

2006/08 -
第65 回応用物理学会学術講演会現地実行委員　現地実行委員

2004/09 -
第65 回応用物理学会学術講演会現地実行委員　現地実行委員

2004/09 -

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Professional Memberships 4

日本応用物理学会
日本金属学会
日本物理学会
日本応用磁気学会

Research Areas 3

Nanotechnology/Materials / Crystal engineering /
Nanotechnology/Materials / Applied materials /
Nanotechnology/Materials / Structural and functional materials /

Papers 269

Spin–orbit torque magnetization switching in CoFeB/Ta/CoFeB tri-layer thin films Peer-reviewed

Koki Okada, Yoshiaki Saito, Nobuki Tezuka

AIP Advances　16　(2)　2026/02/01
Publisher: AIP Publishing
DOI： 10.1063/9.0001011 　

eISSN： 2158-3226

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Spin–orbit torque magnetoresistive random-access memory (SOT-MRAM) with a perpendicularly magnetized ferromagnet (PMF) is a promising candidate for future low-power and high-performance non-volatile memory. However, conventional SOT devices require an external in-plane magnetic field to achieve deterministic magnetization switching, which is a major obstacle for high-density integration. To overcome this issue, we investigate field-free SOT switching in a CoFeB(PMF)/Ta/CoFeB(IMF) trilayer structure, where a Ta layer separates the PMF and an in-plane magnetized ferromagnet (IMF). We successfully demonstrate deterministic field-free magnetization switching in this trilayer system. The switching current density (Jc) was systematically investigated as a function of the Ta and CoFeB(IMF) layer thicknesses, revealing an optimal structure with a significantly reduced. At the optimal thickness of tTa = 5.0 nm and tIMF = 2.0 nm, the switching current density was minimized. To elucidate the origin of this high efficiency, we performed anomalous Hall effect measurements. A large current-induced loop shift was observed, corresponding to a giant effective magnetic field that assists the magnetization reversal. The efficiency of this current-induced field was found to be enhanced by a factor of 4.5 in the trilayer structure compared to a bilayer control sample. We attribute this giant assistance effect to the IMF layer, which enables both the symmetry breaking required for field-free switching and a dramatic reduction in the switching current. These findings provide a new and effective pathway for developing practical, field-free, and low-power SOT-MRAM devices.
Microwave Absorption Properties of Fe<sub>3</sub>B–Fe Composite Powder Peer-reviewed

Masashi Matsuura, Shuhei Miyazaki, Gaku Ishida, Saijian Ajia, Mitsuharu Sato, Nobuki Tezuka, Satoshi Sugimoto

MATERIALS TRANSACTIONS　66　(12)　1599-1604　2025/12/01
Publisher: Japan Institute of Metals
DOI： 10.2320/matertrans.mt-m2025079 　

ISSN： 1345-9678

eISSN： 1347-5320
Room temperature ferromagnetism in polymorphic (Cr,Mn)Te films Peer-reviewed

Mihyeon Kim, Ryoga Nakajima, Takashi Harumoto, Yi Shuang, Daisuke Ando, Nobuki Tezuka, Yuta Saito, Yuji Sutou

APL MATERIALS　13　(6)　2025/06

DOI： 10.1063/5.0266675 　

ISSN： 2166-532X
Field-free spin-orbit torque switching and large dampinglike spin-orbit torque efficiency in synthetic antiferromagnetic systems using interfacial Dzyaloshinskii-Moriya interaction Peer-reviewed

Yoshiaki Saito, Shoji Ikeda, Nobuki Tezuka, Hirofumi Inoue, Tetsuo Endoh

Physical Review B　108　(2)　2023/07/20
Publisher: American Physical Society (APS)
DOI： 10.1103/physrevb.108.024419 　

ISSN： 2469-9950

eISSN： 2469-9969
Deterministic Current‐Induced Perpendicular Switching in Epitaxial Co/Pt Layers without an External Field Peer-reviewed

Jeongchun Ryu, Can Onur Avci, Moojune Song, Mantao Huang, Ryan Thompson, Jiseok Yang, San Ko, Shutaro Karube, Nobuki Tezuka, Makoto Kohda, Kab‐Jin Kim, Geoffrey S. D. Beach, Junsaku Nitta

Advanced Functional Materials　2023/07/02
Publisher: Wiley
DOI： 10.1002/adfm.202209693 　

ISSN： 1616-301X

eISSN： 1616-3028
Magnetic Switching Properties for Synthetic Antiferromagntic Layers with Perpendicular Easy Magnetic Anisotropy Peer-reviewed

N. Tezuka, S. Fujikawa, H. Akatani, M. Matsuura, S. Sugimoto, Y. Saito

2023 IEEE International Magnetic Conference - Short Papers (INTERMAG Short Papers)　2023/05
Publisher: IEEE
DOI： 10.1109/intermagshortpapers58606.2023.10228461 　
Low magnetic damping constant in half-metallic Co2FeAl Heusler alloy thin films grown by molecular beam epitaxy Peer-reviewed

Takayuki Hojo, Nobuki Tezuka, Takafumi Nakano, Masakiyo Tsunoda, Mikihiko Oogane

AIP Advances　13　(2)　025204　2023/02/01

DOI： 10.1063/9.0000419 　
Enhancement of microwave absorption properties using spinodally decomposed Fe–Cr–Co flakes Peer-reviewed

Saijian Ajia, Hirotaka Asa, Mitsuharu Sato, Masashi Matsuura, Nobuki Tezuka, Satoshi Sugimoto

Journal of Magnetism and Magnetic Materials　564　(Part2)　170200-1-170200-11　2022/12/15
Publisher: Elsevier BV
DOI： 10.1016/j.jmmm.2022.170200 　

ISSN： 0304-8853
Development of an alternative approach for electromagnetic wave absorbers using Fe–Cr–Co alloy powders Peer-reviewed

Saijian Ajia, Hirotaka Asa, Yuichiro Toyoda, Mitsuharu Sato, Masashi Matsuura, Nobuki Tezuka, Satoshi Sugimoto

Journal of Alloys and Compounds　903　163920-163920　2022/05
Publisher: Elsevier BV
DOI： 10.1016/j.jallcom.2022.163920 　

ISSN： 0925-8388
Permeability and Noise Suppression Property of Resin Composite with Fe Flake Peer-reviewed

Yuichiro Toyoda, Saijian Ajia, Mitsuharu Sato, Masashi Matsuura, Nobuki Tezuka, Yasushi Endo, Satoshi Sugimoto

IEEJ Transactions on Fundamentals and Materials　142　(2)　45-51　2022/02/01
Publisher: Institute of Electrical Engineers of Japan (IEE Japan)
DOI： 10.1541/ieejfms.142.45 　

ISSN： 0385-4205

eISSN： 1347-5533
Electromagnetic Wave Absorption Properties of Resin Composites Containing α-Fe/Co_0.5Fe_2.5O₄ Mixed Powders Peer-reviewed

Hirotaka ASA, Saijian AJIA, Mitsuharu SATO, Masashi MATSUURA, Nobuki TEZUKA, Satoshi SUGIMOTO

Journal of the Japan Society of Powder and Powder Metallurgy　68　(9)　347-355　2021/09/15
Publisher: Japan Society of Powder and Powder Metallurgy
DOI： 10.2497/jjspm.68.347 　

ISSN： 0532-8799

eISSN： 1880-9014
Antiferromagnetic interlayer exchange coupling and large spin Hall effect in multilayer systems with Pt/Ir/Pt and Pt/Ir layers Peer-reviewed

Yoshiaki Saito, Nobuki Tezuka, Shoji Ikeda, Tetsuo Endoh

Physical Review B　104　(6)　2021/08/23
Publisher: American Physical Society (APS)
DOI： 10.1103/physrevb.104.064439 　

ISSN： 2469-9950

eISSN： 2469-9969
Optical and Electrical Properties of InxGa1-xSe Mixed Crystal Grown from Indium Flux by Traveling Heater Method Peer-reviewed

Yohei Sato, Chao Tang, Katsuya Watanabe, Mayu Nakajima, Takuya Yamamoto, Nobuki Tezuka, Tadao Tanabe, Yutaka Oyama

JOURNAL OF ELECTRONIC MATERIALS　50　(5)　2649-2655　2021/05

DOI： 10.1007/s11664-020-08689-4 　

ISSN： 0361-5235

eISSN： 1543-186X
W thickness dependence of spin Hall effect for (W/Hf)-multilayer electrode/CoFeB/MgO systems with flat and highly (100) oriented MgO layer Peer-reviewed

Y. Saito, N. Tezuka, S. Ikeda, T. Endoh

AIP Advances　11　(2)　025007-1-025007-6　2021/02

DOI： 10.1063/9.0000011 　
Magnetic Properties and Microstructure of W, La Added Sm₂Fe₁₇N₃ Powders

Masashi MATSUURA, Shiho SUZUKI, Kuniko YAMAMOTO, Nobuki TEZUKA, Satoshi SUGIMOTO

Journal of the Japan Society of Powder and Powder Metallurgy　67　(12)　682-687　2020/12/15
Publisher: Japan Society of Powder and Powder Metallurgy
DOI： 10.2497/jjspm.67.682 　

ISSN： 0532-8799

eISSN： 1880-9014
Preparation of Highly Heat–Resistant Sm–Fe–N Magnetic Powder by Reduction–Diffusion Process Peer-reviewed

Ruka Matsuda, Masashi Matsuura, Nobuki Tezuka, Satoshi Sugimoto, Takashi Ishikawa, Yukinobu Yoneyama

MATERIALS TRANSACTIONS　61　(11)　2201-2207　2020/11/01
Publisher: Japan Institute of Metals
DOI： 10.2320/matertrans.mt-m2020185 　

ISSN： 1345-9678

eISSN： 1347-5320
Microstructural changes in high-coercivity Zn-bonded Sm-Fe-N magnets Peer-reviewed

Masashi Matsuura, Kuniko Yamamoto, Nobuki Tezuka, Satoshi Sugimoto

Journal of Magnetism and Magnetic Materials　510　166943-166943　2020/09
Publisher: Elsevier BV
DOI： 10.1016/j.jmmm.2020.166943 　

ISSN： 0304-8853
Preparation of Sm−Fe−N Bulk Magnets with High Maximum Energy Products Peer-reviewed

R. Matsunami, M. Matsuura, N. Tezuka, S. Sugimoto

Journal of the Magnetics Society of Japan　44　(3)　64-69　2020/05/01
Publisher: The Magnetics Society of Japan
DOI： 10.3379/msjmag.2005r003 　

ISSN： 1882-2924

eISSN： 1882-2932
Large spin Hall effect and increase in perpendicular magnetic anisotropy in artificially synthesized amorphous W/Hf multilayer/CoFeB system Peer-reviewed

Saito, Y., Tezuka, N., Ikeda, S., Endoh, T.

Applied Physics Letters　116　(13)　132401-1-132401-5　2020/03

DOI： 10.1063/5.0002642 　
Anomalous Spin-Orbit Field via the Rashba-Edelstein Effect at the W/Pt Interface Peer-reviewed

Shutaro Karube, Nobuki Tezuka, Makoto Kohda, Junsaku Nitta

Physical Review Applied　13　(2)　2020/02

DOI： 10.1103/PhysRevApplied.13.024009 　

eISSN： 2331-7019
Terahertz wave generation via difference frequency generation using 2D In<inf>x</inf>Ga<inf>1−x</inf>Se crystal grown from indium flux Peer-reviewed

Yohei Sato, Chao Tang, Katsuya Watanabe, Junya Ohsaki, Takuya Yamamoto, Nobuki Tezuka, Tadao Tanabe, Yutaka Oyama

Optics Express　28　(1)　472-477　2020

DOI： 10.1364/OE.28.000472 　

eISSN： 1094-4087
Spin Hall effect investigated by spin Hall magnetoresistance in Pt100−xAux/CoFeB systems Peer-reviewed

SAITO Yoshiaki

AIP Advances　9　125312-1-125312-5　2019/12

DOI： 10.1063/1.5129889 　
高特性Sm-Fe-Ｎ系バルク磁石の組織と磁気特性

松浦昌志, 松南諒, 西島佑樹, 手束展規, 杉本諭

電気学会マグネティックス研究会資料（MAG-18-197～208）　61-64　2019/12
Fabrication of Co2Fe(Al,Si) and Co2Fe(Al,Si)/MgO on Ge(111) Substrate and Its Magnetic Properties International-journal Peer-reviewed

Kohei Kataoka, Nobuki Tezuka, Masashi Matsuura, Satoshi Sugimoto

Journal of Electronic Science and Technology　17　(2)　109-115　2019/11/11

DOI： 10.11989/JEST.1674-862X.71128011 　
Fabrication of Anisotropic Nd-Fe-B Powders by Ta Sputtering Peer-reviewed

Moe Kimura, Masashi Matsuura, Nobuki Tezuka, Satoshi Sugimoto

Materials Transactions　60　(5)　830-836　2019/04

DOI： 10.2320/matertrans.M2019003 　
Cr拡散Sm₂Fe₁₇N_xコア・シェル磁石粉末の作製 Peer-reviewed

松田瑠香, 鑓水啓介, 松浦昌志, 手束展規, 杉本諭, 石川尚, 米山幸伸

粉体および粉末冶金　66　(3)　116-121　2019/03

DOI： 10.2497/jjspm.66.116 　
Preparation of Mn-diffused Sm-Fe-N core-shell powder by reduction-diffusion process. Peer-reviewed

Masashi Matsuura, Keisuke Yarimizu, Yohei Osawa, Nobuki Tezuka, Satoshi Sugimoto, Takashi Ishikawa, Yukinobu Yoneyama

Journal of Magnetism and Magnetic Materials　471　310-314　2019/02

DOI： 10.1016/j.jmmm.2018.09.084 　
Increase in spin-Hall effect and influence of anomalous Nernst effect on spin-Hall magnetoresistance in β-phase and α-phase W <inf>100-x</inf> Ta <inf>x</inf> /CoFeB systems Peer-reviewed

Yoshiaki Saito, Nobuki Tezuka, Shoji Ikeda, Hideo Sato, Tetsuo Endoh

Applied Physics Express　12　2019/01/01

DOI： 10.7567/1882-0786/ab1a66 　

ISSN： 1882-0778
低酸素化によるSm-Fe-N系バルク磁石の高特性化

松浦昌志, 西島佑樹, 手束展規, 杉本諭

電気学会マグネティックス研究会資料　MAG-18-184～192　41-45　2018/12
Increase of energy products of Zn-bonded Sm-Fe-N magnets with low oxygen content. Peer-reviewed

Masashi Matsuura, Yuki Nishijima, Nobuki Tezuka, Satoshi Sugimoto, Tetsuya Shoji, Noritsugu Sakuma

Journal of Magnetism and Magnetic Materials　467　64-68　2018/12
Publisher: Elsevier BV
DOI： 10.1016/j.jmmm.2018.07.064 　

ISSN： 0304-8853
ε-Fe₂O₃微粒子の水素還元による相変化と磁気特性

The Papers of Technical Meeting on "Magnetics", IEE Japan　MAG-18-081～097　71-76　2018/08
Voltage control of a magnetic switching field for magnetic tunnel junctions with low resistance and perpendicular magnetic anisotropy Peer-reviewed

N. Tezuka, S. Oikawa, M. Matsuura, S. Sugimoto, K. Nishimura, T. Irisawa, Y. Nagamine, K. Tsunekawa

AIP Advances　8　(5)　55922-1-55922-5　2018/05/01
Publisher: American Institute of Physics Inc.
DOI： 10.1063/1.5006398 　

ISSN： 2158-3226

eISSN： 2158-3226
High coercive Zn-bonded Sm-Fe-N magnets prepared using fine Zn particles with low oxygen content Peer-reviewed

Masashi Matsuura, Tomoki Shiraiwa, Nobuki Tezuka, Satoshi Sugimoto, Tetsuya Shoji, Noritsugu Sakuma, Kazuaki Haga

Journal of Magnetism and Magnetic Materials　452　243-248　2018/04/15
Publisher: Elsevier B.V.
DOI： 10.1016/j.jmmm.2017.12.059 　

ISSN： 0304-8853
Interfacial crystal structures and non-local spin signals of Co2FeAl0.5Si0.5/n-GaAs junctions Peer-reviewed

Kohei Kataoka, Tatsuya Saito, Nobuki Tezuka, Masashi Matsuura, Satoshi Sugimoto

IEEE Transactions on Magnetics　54　(1)　4400103-1-4400103-3　2018/01/01
Publisher: Institute of Electrical and Electronics Engineers Inc.
DOI： 10.1109/TMAG.2017.2756986 　

ISSN： 0018-9464
Nd-CuスパッタリングによるNd-Fe-B系超微細粉末の高保磁力化

飯島亜美, 松浦昌志, 手束展規, 杉本諭, 東, 宇根康裕, 久保博一, 溝口徹彦, 入山恭彦, 佐川眞人, インターメタリックス

電気学会マグネティックス研究会資料（MAG-17-186～103 ）　83-88　2017/08/08
α-Fe/FePd複合粉末の作製と磁気特性

阿部格, 小川智之, 松浦昌志, 手束展規, 齊藤伸, 杉本諭

電気学会マグネティックス研究会資料（MAG-17-186～103 ）　69-74　2017/08/08
Crystal, electronic structures and spin signals Co₂FeAl_0.5Si_0.5/n-GaAs junctions. Peer-reviewed

N. Tezuka, K. Kataoka, T. Saito, M. Matsuura, S. Sugimoto

2017 IEEE International Magnetics Conference (INTERMAG)　2017/08

DOI： 10.1109/INTMAG.2017.8007723 　
Preparation of Composite Magnetic Nanoparticles by Arc Plasma Deposition Peer-reviewed

Masashi Matsuura, Takuya Igarashi, tetsuro Yamamoto, Nobuki Tezuka, Satoshi Sugimoto

Journal of the Japan Society of Powder and Powder Metallurgy　64　(7)　364-371　2017/07/15

DOI： 10.2497/jjspm.64.364 　
Effect of hydrogenation disproportionation conditions on magnetic anisotropy in Nd-Fe-B powder prepared by dynamic hydrogenation disproportionation desorption recombination Peer-reviewed

Masao Yamazaki, Takashi Horikawa, Chisato Mishima, Masashi Matsuura, Nobuki Tezuka, Satoshi Sugimoto

AIP ADVANCES　7　(5)　056220　2017/05

DOI： 10.1063/1.4975697 　

ISSN： 2158-3226
Magnetoresistance ratio through Si semiconductor using a magnetic tunnel junction Peer-reviewed

N. Tezuka, S. Oikawa, M. Matsuura, S. Sugimoto, Y. Saito

IEEE International magnetic conference 2017 (Intermag 2017)　CN-13　2017/04
Room temperature observation of high spin polarization in post annealed Co2FeSi/MgO/n+-Si Peer-reviewed

A. Tiwari, T. Inokuchi, M. Ishikawa, H. Sugiyama, N. Tezuka, Y. Saito

Jpn. J. Appl. Phys.　56　04CD05-1-04CD05-5　2017/02/24

DOI： 10.7567/JJAP.56.04CD05 　
Effect of hydrogenation disproportionation conditions on magnetic anisotropy in Nd-Fe-B powder prepared by dynamic hydrogenation disproportionation desorption recombination. Peer-reviewed

TEZUKA Nobuki

AIP Advances　7　(5)　056220-1-056220-8　2017/02
Study of an Al-Ca Alloy with Low Young's Modulus Peer-reviewed

Jun Yu, Yasuo Ishiwata, Yoshihiro Taguchi, Daisuke Shimosaka, Ryosuke Taniguchi, Takutoshi Kondo, Nobuki Tezuka

LIGHT METALS 2017　167-171　2017

DOI： 10.1007/978-3-319-51541-0_23 　

ISSN： 2367-1181
Improvement of Coercivity of Nd-Fe-B Powder by Nd-Cu Sputtering Peer-reviewed

Ami Iijima, Masashi Matsuura, Nobuki Tezuka, Satoshi Sugimoto, Yasuhiro Une, Hirokazu Kubo, Masato Sagawa

MATERIALS TRANSACTIONS　58　(5)　825-828　2017

DOI： 10.2320/matertrans.M2016448 　

ISSN： 1345-9678

eISSN： 1347-5320
Room temperature observation of large spin accumulation and transport signals in post annealed Co2FeSi/MgO/n+-Si on insulator devices Peer-reviewed

A. Tiwari, T. Inokuchi, M. Ishikawa, H. Sugiyama, N. Tezuka, Y. Saito

2016 International conference on solid state devices and materials (SSDM 2016)　2016/09
Effect of post annealing on spin accumulation and transport signals in Co2FeSi/MgO/n(+)-Si on insulator devices Peer-reviewed

Ajay Tiwari, Tomoaki Inokuchi, Mizue Ishikawa, Hideyuki Sugiyama, Nobuki Tezuka, Yoshiaki Saito

AIP ADVANCES　6　(7)　075119　2016/07

DOI： 10.1063/1.4960210 　

ISSN： 2158-3226
High-Coercivity Fe-Co Nanoparticles Prepared by Pulsed Arc Plasma Deposition Peer-reviewed

Daiki Horiyama, Masashi Matsuura, Tetsuro Yamamoto, Nobuki Tezuka, Satoshi Sugimoto

MATERIALS TRANSACTIONS　57　(2)　207-211　2016/02

DOI： 10.2320/matertrans.MAW201510 　

ISSN： 1345-9678

eISSN： 1347-5320
Spin accumulation signals in CoFe/MgO/n+-Si devices deposited on Si (1×1) and Si (2×1) surfaces Peer-reviewed

Yoshiaki Saito, Mizue Ishikawa, Tomoaki Inokuchi, Hideyuki Sugiyama, Kohei Hamaya, Nobuki Tezuka

Joint MMM/Intermag Conference, 2016　2016/01
Spin Injection, Transport, and Detection in a Lateral Spin Transport Devices with Co2FeAl0.5Si0.5/n-GaAs, Co2FeSi/MgO/n-Si, and CoFe/MgO/n-Si Junctions Peer-reviewed

Nobuki Tezuka, Yoshiaki Saito

MATERIALS TRANSACTIONS　57　(6)　767-772　2016

DOI： 10.2320/matertrans.ME201502 　

ISSN： 1345-9678

eISSN： 1347-5320
Perpendicular Magnetic Tunnel Junctions With Low Resistance-Area Product: High Output Voltage and Bias Dependence of Magnetoresistance Peer-reviewed

N. Tezuka, S. Oikawa, I. Abe, M. Matsuura, S. Sugimoto, K. Nishimura, T. Seino

IEEE MAGNETICS LETTERS　7　3104104-3104204　2016

DOI： 10.1109/LMAG.2016.2584582 　

ISSN： 1949-307X
FeCo-Ti-N系異方性薄膜における結晶構造と磁気特性の膜厚依存性

河原崇範, 松浦昌志, 手束展規, 杉本諭

電気学会マグネティックス研究会資料,MAG-15-160　33-37　2015/12/01
Influence of Swaging on the Magnetic Properties of Zn-Bonded Sm-Fe-N Magnets Peer-reviewed

Kohei Kataoka, Masashi Matsuura, Nobuki Tezuka, Satoshi Sugimoto

MATERIALS TRANSACTIONS　56　(10)　88-92　2015/10

DOI： 10.2320/matertrans.M2015190 　

ISSN： 1345-9678

eISSN： 1347-5320
Influence of Si surface on spin accumulation and transport signals in CoFe/MgO/n+-Si junctions Peer-reviewed

Mizue Ishikawa, Tomoaki Inokuchi, Hideyuki Sugiyama, Nobuki Tezuka, Kohei Hamaya, Yoshiaki Saito

2015 International conference on solid state devices and materials (SSDM 2015)　2015/09
Influence of miniaturization of the CoFe/MgO/n+-Si devices on magnitude of magnetoresistance Peer-reviewed

Hideyuki Sugiyama, Mizue Ishikawa, Tomoaki Inokuchi, Yoshiaki Saito, Nobuki Tezuka

International Colloquium on Magnetic Films and Surfaces 2015 (ICMFS 2015)　2015/06
Spin accumulation and transport signals in Heusler Co2FeSi/MgO/n+-Si on insulator devices Peer-reviewed

Yoshiaki Saito, Mizue Ishikawa, Tomoaki Inokuchi, Hideyuki Sugiyama, Kohei Hamaya, Nobuki Tezuka

20th International conference on Magnetism (ICM 2015)　2015/06
Increased uniaxial perpendicular anisotropy in tetragonally distorted FeCo-Ti-N films Peer-reviewed

Masashi Matsuura, Nobuki Tezuka, Satoshi Sugimoto

JOURNAL OF APPLIED PHYSICS　117　(17)　17A738　2015/05

DOI： 10.1063/1.4916763 　

ISSN： 0021-8979

eISSN： 1089-7550
Correlation between amplitude of spin accumulation signals investigated by Hanle effect measurement and effective junction barrier height in CoFe/MgO/n(+)-Si junctions Peer-reviewed

Y. Saito, M. Ishikawa, H. Sugiyama, T. Inokuchi, K. Hamaya, N. Tezuka

JOURNAL OF APPLIED PHYSICS　117　(17)　17C707　2015/05

DOI： 10.1063/1.4907242 　

ISSN： 0021-8979

eISSN： 1089-7550
Structural, magnetic and electric transport properties for Co2FeAl0.5Si0.5/n-GaaS junctions Peer-reviewed

Nobuki Tezuka, Tatsuya Saito, Masashi Matsuura, Satoshi Sugimoto

Solid State Phenomena　233-234　411-414　2015
Publisher: Trans Tech Publications Ltd
DOI： 10.4028/www.scientific.net/SSP.233-234.411 　

ISSN： 1662-9779
Effects of Hydrogenation-Disproportionation-Desorption-Recombination Processing Parameters on the Particle Size of Ultrafine Jet-Milled Nd-Fe-B Powders Peer-reviewed

Michihide Nakamura, Masashi Matsuura, Nobuki Tezuka, Satoshi Sugimoto, Yasuhiro Une, Hirokazu Kubo, Masato Sagawa

MATERIALS TRANSACTIONS　56　(1)　129-134　2015/01

DOI： 10.2320/matertrans.M2014273 　

ISSN： 1345-9678

eISSN： 1347-5320
Influence of interface roughness in CoFe/MgO/n+-Si junctions on spin accumulation and spin transport signals Peer-reviewed

Mizue Ishikawa, Hideyuki Sugiyama, Tomoaki Inokuchi, Tetsufumi Tanamoto, Kohei Hamaya, Nobuki Tezuka, Yoshiaki Saito

59th annual Magnetism & Magnetic Materials Conference (MMM2014)　2014/11
Comparison of Spin Signals Between 3T Hanle and 4T Non-Local Methods for Co2Fe(Al,Si)/n-GaAs Junctions Peer-reviewed

Nobuki Tezuka, Tatsuya Saito, Masashi Matsuura, Satoshi Sugimoto

IEEE TRANSACTIONS ON MAGNETICS　50　(11)　2600204　2014/11

DOI： 10.1109/TMAG.2014.2325942 　

ISSN： 0018-9464

eISSN： 1941-0069
Effect of Annealing on Magnetic Properties of Ultrafine Jet-Milled Nd-Fe-B Powders Peer-reviewed

Michihide Nakamura, Masashi Matsuura, Nobuki Tezuka, Satoshi Sugimoto, Yasuhiro Une, Hirokazu Kubo, Masato Sagawa

MATERIALS TRANSACTIONS　55　(10)　1582-1586　2014/10

DOI： 10.2320/matertrans.MAW201402 　

ISSN： 1345-9678

eISSN： 1347-5320
Microstructure and coercivity of nitrided Mn-Sn-based alloys Peer-reviewed

Masashi Matsuura, Keita Isogai, Keita Shinaji, Nobuki Tezuka, Satoshi Sugimoto

JOURNAL OF ALLOYS AND COMPOUNDS　605　208-212　2014/08

DOI： 10.1016/j.jallcom.2014.03.158 　

ISSN： 0925-8388

eISSN： 1873-4669
Large spin-accumulation signal in Si for epitaxial CoFe/highly (100)-textured MgO/Si devices Peer-reviewed

H. Sugiyama, M. Ishikawa, T. Inokuchi, T. Tanamoto, Y. Saito, N. Tezuka

SOLID STATE COMMUNICATIONS　190　49-52　2014/07

DOI： 10.1016/j.ssc.2014.03.019 　

ISSN： 0038-1098

eISSN： 1879-2766
Local magnetoresistance through Si and its bias voltage dependence in ferromagnet/MgO/silicon-on-insulator lateral spin valves Peer-reviewed

Y. Saito, T. Tanamoto, M. Ishikawa, H. Sugiyama, T. Inokuchi, K. Hamaya, N. Tezuka

JOURNAL OF APPLIED PHYSICS　115　(17)　17C514　2014/05

DOI： 10.1063/1.4866699 　

ISSN： 0021-8979

eISSN： 1089-7550
Magnetic properties of amorphous Fe-B / spinel-ferrite composite particles prepared by the ferrite plating method Peer-reviewed

K. Shimba, Y. Hoshi, M. Matsuura, N. Tezuka, S. Sugimoto

Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy　61　S231-S233　2014
Publisher: Journal of the Japan Society of Powder and Powder Metallurgy
DOI： 10.2497/jjspm.61.S231 　

ISSN： 0532-8799
Spin injection, detection and local magnetoresistance through Si at room temperature in ferrmagnet/MgO/Si lateral spin valves Invited Peer-reviewed

Y. Saito, M. Ishikawa, T. Inokuchi, H. Sugiyama, T. Tanamoto, N. Tezuka, K. Hamaya

IEEE International nanoelectronics conference, 2014 (IEEE INEC 2014)　2014
HDDR法利用によるNd-Fe-B系焼結磁石向け超微細原料粉末作製法の開発

中村通秀, 松浦昌志, 手束展規, 杉本諭, 宇根康裕, 久保博一, 佐川眞人

電気学会マグネティックス研究会資料,MAG-13-107　25-30　2013/12/02
Maximum magnitude in bias-dependent spin accumulation signals of CoFe/MgO/Si on insulator devices Peer-reviewed

M. Ishikawa, H. Sugiyama, T. Inokuchi, T. Tanamoto, K. Hamaya, N. Tezuka, Y. Saito

JOURNAL OF APPLIED PHYSICS　114　(24)　243904　2013/12

DOI： 10.1063/1.4856955 　

ISSN： 0021-8979

eISSN： 1089-7550
Local magnetoresistance through Si at room temperature and its bias voltage dependence in CoFe/MgO/SOI lateral spin valves Peer-reviewed

Y. Saito, T. Tanamoto, M. Ishikawa, H. Sugiyama, T. Inokuchi, K. Hamaya, N. Tezuka

58th Annual Conference on Magnetism and Magnetic Materials (2013 MMM Conference)　HB-04　2013/11
Influence of Heat Treatment on the Microstructure and Magnetic Properties of Mn-Sn-Co-N Alloys Peer-reviewed

Keita Shinaji, Tsuyoshi Mase, Keita Isogai, Masashi Matsuura, Nobuki Tezuka, Satoshi Sugimoto

MATERIALS TRANSACTIONS　54　(10)　2007-2010　2013/10

DOI： 10.2320/matertrans.MAW201312 　

ISSN： 1345-9678

eISSN： 1347-5320
Spin injection, transport, and detection at room temperature in a lateral spin transport device with Co2FeAl0.5Si 0.5/n-GaAs schottky tunnel junctions Peer-reviewed

Tatsuya Saito, Nobuki Tezuka, Masashi Matsuura, Satoshi Sugimoto

Applied Physics Express　6　(10)　103006　2013/10

DOI： 10.7567/APEX.6.103006 　

ISSN： 1882-0778 1882-0786
Four-terminal nonlocal signals in lateral spin transport devices with variously ordered Co2FeAl0.5Si0.5 full-Heusler alloy electrodes Peer-reviewed

Tatsuya Saito, Nobuki Tezuka, Masashi Matsuura, Satoshi Sugimoto

Applied Physics Letters　103　(12)　122401　2013/09/16

DOI： 10.1063/1.4821451 　

ISSN： 0003-6951
Correlation between the intensities of differential conductance curves and the spin accumulation signals in Si for CoFe/MgO/SOI devices Peer-reviewed

M. Ishikawa, T. Inokuchi, H. Sugiyama, K. Hamaya, N. Tezuka, Y. Saito

International conference on solid state devices and materials (SSDM2013)　2013/09
Crystal Structures and Spin Injection Signals of Si/Mg/MgO/Co2FeAl0.5Si0.5 Junctions Peer-reviewed

Takashi Onodera, Masahiro Yoshida, Nobuki Tezuka, Masashi Matsuura, Satoshi Sugimoto, Yoshiaki Saito

MATERIALS TRANSACTIONS　54　(8)　1392-1395　2013/08

DOI： 10.2320/matertrans.M2013139 　

ISSN： 1345-9678

eISSN： 1347-5320
Preparation of ultrafine jet-milled powders for Nd-Fe-B sintered magnets using hydrogenation-disproportionation-desorption-recombination and hydrogen decrepitation processes Peer-reviewed

Michihide Nakamura, Masashi Matsuura, Nobuki Tezuka, Satoshi Sugimoto, Yasuhiro Une, Hirokazu Kubo, Masato Sagawa

APPLIED PHYSICS LETTERS　103　(2)　22404　2013/07

DOI： 10.1063/1.4813399 　

ISSN： 0003-6951
Non-Local and Local Spin Signals in a Lateral Spin Transport Device With Co2FeAl0.5Si0.5/n-GaAs Schottky Tunnel Junctions Peer-reviewed

Tatsuya Saito, Nobuki Tezuka, Masashi Matsuura, Satoshi Sugimoto

IEEE TRANSACTIONS ON MAGNETICS　49　(7)　4327-4330　2013/07

DOI： 10.1109/TMAG.2013.2248053 　

ISSN： 0018-9464

eISSN： 1941-0069
Microwave absorption properties of polymer composites with amorphous Fe-B and Ni-Zn-Co ferrite nanoparticles Peer-reviewed

Kazuaki Shimba, Shozo Yuki, Nobuki Tezuka, Satoshi Sugimoto

JOURNAL OF THE KOREAN PHYSICAL SOCIETY　62　(12)　2123-2127　2013/07

DOI： 10.3938/jkps.62.2123 　

ISSN： 0374-4884
Preparation of ultrafine jet-milled powders for Nd-Fe-B sintered magnets using hydrogenation-disproportionation-desorption-recombination and hydrogen decrepitation processes Peer-reviewed

Michihide Nakamura, Masashi Matsuura, Nobuki Tezuka, Satoshi Sugimoto, Yasuhiro Une, Hirokazu Kubo, Masato Sagawa

APPLIED PHYSICS LETTERS　103　(2)　022404　2013/07

DOI： 10.1063/1.4813399 　

ISSN： 0003-6951
Three-Terminal Hanle Signals in Schottky Tunnel Junctions with Co2FeAl0.5Si0.5 Full-Heusler Alloy Electrodes Deposited at Various Temperatures Peer-reviewed

Tatsuya Saito, Nobuki Tezuka, Masashi Matsuura, Satoshi Sugimoto

JAPANESE JOURNAL OF APPLIED PHYSICS　52　(6)　UNSP 063001　2013/06

DOI： 10.7567/JJAP.52.063001 　

ISSN： 0021-4922

eISSN： 1347-4065
Three-Terminal Hanle Signals in Schottky Tunnel Junctions with Co2FeAl0.5Si0.5 Full-Heusler Alloy Electrodes Deposited at Various Temperatures Peer-reviewed

Tatsuya Saito, Nobuki Tezuka, Masashi Matsuura, Satoshi Sugimoto

JAPANESE JOURNAL OF APPLIED PHYSICS　52　(6)　2013/06

DOI： 10.7567/JJAP.52.063001 　

ISSN： 0021-4922

eISSN： 1347-4065
Fabrication of (001)-oriented MgO thin filins on si substrates Peer-reviewed

Takashi Onodera, Masahiro Yoshida, Nobuki Tezuka, Satoshi Sugimoto, Yoshiaki Saito

Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals　77　(3)　89-93　2013/03

DOI： 10.2320/jinstmet.77.89 　

ISSN： 0021-4876
Crystal structure and spin conduction property of Co2FeAl 0.5Si0.5 full-heusler alloy thin films deposited on Si substrates Peer-reviewed

Masahiro Yoshida, Takashi Onodera, Nobuki Tezuka, Satoshi Sugimoto, Yoshiaki Saito

Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals　77　(3)　85-88　2013/03

DOI： 10.2320/jinstmet.77.85 　

ISSN： 0021-4876
Crystal structure and spin conduction property of Co2FeAl 0.5Si0.5 full-heusler alloy thin films deposited on Si substrates Peer-reviewed

Masahiro Yoshida, Takashi Onodera, Nobuki Tezuka, Satoshi Sugimoto, Yoshiaki Saito

Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals　77　(3)　85-88　2013/03

DOI： 10.2320/jinstmet.77.85 　

ISSN： 0021-4876
Spin accumulation in Si for CoFe/MgO/Mg/Si-on-insulator devices Peer-reviewed

H. Sugiyama, M. Ishikawa, T. Inokuchi, H. T. Tanamoto, K. Hamaya, Y. Saito, N. Tezuka

Joint MMM/Intermag Conference, 2013　2013/01
Non-local and local spin signals in a lateral spin transport device with Co2FeAl0.5Si0.5/n-GaAs schottky tunnel junctions Peer-reviewed

Tatsuya Saito, Nobuki Tezuka, Masashi Matsuura, Satoshi Sugimoto

IEEE Transactions on Magnetics　49　(7)　4327-4330　2013

DOI： 10.1109/TMAG.2013.2248053 　

ISSN： 0018-9464
Fabrication of (001)-Oriented MgO Thin Films on Si Substrates Peer-reviewed

Takashi Onodera, Masahiro Yoshida, Nobuki Tezuka, Satoshi Sugimoto, Yoshiaki Saito

JOURNAL OF THE JAPAN INSTITUTE OF METALS　77　(3)　89-93　2013

DOI： 10.2320/jinstmet.77.89 　

ISSN： 0021-4876

eISSN： 1880-6880
Magnetic properties of mnbi fine particles fabricated using hydrogen plasma metal reaction Peer-reviewed

Keita Isogai, Masashi Matsuura, Nobuki Tezuka, Satoshi Sugimoto

Materials Transactions　54　(9)　1673-1677　2013

DOI： 10.2320/matertrans.MAW201306 　

ISSN： 1345-9678
Fabrication of (001)-Oriented MgO Thin Films on Si Substrates Peer-reviewed

Takashi Onodera, Masahiro Yoshida, Nobuki Tezuka, Satoshi Sugimoto, Yoshiaki Saito

JOURNAL OF THE JAPAN INSTITUTE OF METALS　77　(3)　89-93　2013

DOI： 10.2320/jinstmet.77.89 　

ISSN： 0021-4876

eISSN： 1880-6880
Microstructure and magnetic properties of Mn-Sn-N and Mn-Sn-Co-N alloys Peer-reviewed

Keita Isogai, Keita Shinaji, Tsuyoshi Mase, Masashi Matsuura, Nobuki Tezuka, Satoshi Sugimoto

Materials Transactions　54　(7)　1236-1239　2013

DOI： 10.2320/matertrans.M2013113 　

ISSN： 1345-9678
Evaluation of the Microstructural Contribution to the Coercivity of Fine-Grained Nd-Fe-B Sintered Magnets Peer-reviewed

T.Fukada, R.Goto, M.Matsuura, S.Sugimoto, N.Tezuka, Y.Une, M.Sagawa

Materials Transactions　53　(11)　1967-1971　2012/11

DOI： 10.2320/matertrans.MAW201207 　
Spin-Based MOSFETs for Logic and Memory Applications and Spin Accumulation Signals in CoFe/Tunnel Barrier/SOI Devices Peer-reviewed

Yoshiaki Saito, Mizue Ishikawa, Tomoaki Inokuchi, Hideyuki Sugiyama, Tetsufumi Tanamoto, Kohei Hamaya, Nobuki Tezuka

IEEE TRANSACTIONS ON MAGNETICS　48　(11)　2739-2745　2012/11

DOI： 10.1109/TMAG.2012.2202277 　

ISSN： 0018-9464

eISSN： 1941-0069
New materials research for high spin polarized current Invited Peer-reviewed

Nobuki Tezuka

Journal of Magnetism and Magnetic Materials　324　(21)　3588-3592　2012/10

DOI： 10.1016/j.jmmm.2012.02.097 　

ISSN： 0304-8853
New materials research for high spin polarized current Invited Peer-reviewed

Nobuki Tezuka

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS　324　(21)　3588-3592　2012/10

DOI： 10.1016/j.jmmm.2012.02.097 　

ISSN： 0304-8853

eISSN： 1873-4766
Enhancement of Coercivity of Zn-bonded Sm-Fe-N Magnets Prepared by Hot-rolling

D. Ishihara, M. Matsuura, N. Tezuka, S. Sugimoto

Proceedings of the 22nd International Workshop on Rare-Earth Permanent Magnets and their Applications (REPM’ 12), Edited by S. Sugimoto and M. Nakano　292-295　2012/09/02
Crystal Structure and Lattice Constant of Nd-rich Phase in Nd-Fe-B Films

M. Matsuura, N. Tezuka, S. Sugimoto

Proceedings of the 22nd International Workshop on Rare-Earth Permanent Magnets and their Applications (REPM’ 12), Edited by S. Sugimoto and M. Nakano　403-406　2012/09/02
Asymmetric bias voltage dependence in spin accumulation signals observed by the three-terminal Hanle measurements for CoFe/MgO/SOI devices Peer-reviewed

M. Ishikawa, T. Inokuchi, H. Sugiyama, T. Tanamoto, K. Hamaya, N. Tezuka, Y. Saito

International conference on Solid State Devices and Materials (SSDM2012)　2012/09
Microwave Absorption Properties of Highly Filled Polymer Composites with Amorphous Fe-B Particles Peer-reviewed

Kiyotaka Furuta, Kazuaki Shimba, Nobuki Tezuka, Satoshi Sugimoto

Material Transaction　53　(9)　1665-1668　2012/08/25

DOI： 10.2320/matertrans.MAW201203 　
Anisotropy and Damping in CoFeAlSi via Electrical Detection of Ferromagnetic Resonance Peer-reviewed

Lihui Bai, N. Tezuka, M. Kohda, J. Nitta

Jpn. Appl. Phys.　51　083001-1-083001-5　2012/07/31

DOI： 10.1143/JJAP.51.083001 　
Microwave Absorption Properties of Resin Composites with Amorphous Fe-B Particles Peer-reviewed

Shozo Yuki, Kazuaki Shimba, Nobuki Tezuka, Satoshi Sugimoto

JOURNAL OF THE JAPAN INSTITUTE OF METALS　76　(4)　278-282　2012/04

ISSN： 0021-4876

eISSN： 1880-6880
Microstructure evaluation for Dy-free Nd-Fe-B sintered magnets with high coercivity Peer-reviewed

R. Goto, M. Matsuura, S. Sugimoto, N. Tezuka, Y. Une, M. Sagawa

JOURNAL OF APPLIED PHYSICS　111　(7)　07A739　2012/04

DOI： 10.1063/1.3680190 　

ISSN： 0021-8979

eISSN： 1089-7550
Microwave absorption properties of resin composites with amorphous Fe-B particles Peer-reviewed

Shozo Yuki, Kazuaki Shimba, Nobuki Tezuka, Satoshi Sugimoto

Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals　76　(4)　278-282　2012/04

DOI： 10.2320/jinstmet.76.278 　

ISSN： 0021-4876
Spin injection and detection between CoFe/AlOx junctions and SOI investigated by Hanle effect measurements Peer-reviewed

Tomoaki Inokuchi, Mizue Ishikawa, Hideyuki Sugiyama, Yoshiaki Saito, Nobuki Tezuka

JOURNAL OF APPLIED PHYSICS　111　(7)　07C316　2012/04

DOI： 10.1063/1.3677930 　

ISSN： 0021-8979

eISSN： 1089-7550
Temperature and Bias Voltage Dependencies of Spin Injection Signals for CO2FeAl0.5Si0.5/n-GaAs Schottky Tunnel Junction Peer-reviewed

Tatsuya Saito, Nobuki Tezuka, Satoshi Sugimoto

MATERIALS TRANSACTIONS　53　(4)　641-644　2012/04

DOI： 10.2320/matertrans.MBW201113 　

ISSN： 1345-9678

eISSN： 1347-5320
Tunnel magnetoresistance effect in magnetic tunnel junctions with epitaxial Co 2FeAl 0.5Si 0.5 Heusler electrodes on MgO (110) single substrates Peer-reviewed

N. Tezuka, F. Mitsuhashi, S. Sugimoto

Journal of Applied Physics　111　(7)　07C718　2012/04/01

DOI： 10.1063/1.3678586 　

ISSN： 0021-8979
Magnetic and microwave absorption properties of polymer composites with amorphous Fe-B/Ni-Zn ferrite nanoparticles Peer-reviewed

Kazuaki Shimba, Nobuki Tezuka, Satoshi Sugimoto

MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS　177　(2)　251-256　2012/02

DOI： 10.1016/j.mseb.2011.12.002 　

ISSN： 0921-5107
Interfacial Microstructure of Nd2Fe14B/Nd-Rich and Coercivity in Nd-Fe-B Films Peer-reviewed

Masashi Matsuura, Ryota Goto, Nobuki Tezuka, Satoshi Sugimoto

JOURNAL OF THE JAPAN INSTITUTE OF METALS　76　(1)　65-71　2012/01

DOI： 10.2320/jinstmet.76.65 　

ISSN： 0021-4876

eISSN： 1880-6880
Correlation between symmetry-selective transport and spin-dependent resonant tunneling in fully epitaxial Cr/ultrathin-Fe/MgO/Fe(001) magnetic tunnel junctions Peer-reviewed

Tomohiko Niizeki, Hiroaki Sukegawa, Seiji Mitani, Nobuki Tezuka, Koichiro Inomata

APPLIED PHYSICS LETTERS　99　(18)　182508　2011/10

DOI： 10.1063/1.3647578 　

ISSN： 0003-6951

eISSN： 1077-3118
Transmission Electron Microscopy Study on Nd-Rich Phase at the Surface of Nd2Fe14B Phase in Nd-Fe-B Films Peer-reviewed

Masashi Matsuura, Ryota Goto, Nobuki Tezuka, Satoshi Sugimoto

IEEE TRANSACTIONS ON MAGNETICS　47　(10)　3273-3275　2011/10

DOI： 10.1109/TMAG.2011.2148111 　

ISSN： 0018-9464
Electrical Transport Properties and Spin Injection in Co2FeAl0.5Si0.5/GaAs Junctions Peer-reviewed

Tatsuya Saito, Nobuki Tezuka, Satoshi Sugimoto

IEEE TRANSACTIONS ON MAGNETICS　47　(10)　2447-2450　2011/10

DOI： 10.1109/TMAG.2011.2153189 　

ISSN： 0018-9464
Microwave Absorption Properties of Polymer Modified Ni-Zn Ferrite Nanoparticles Peer-reviewed

Kazuaki Shimba, Kiyotaka Furuta, Nobuyuki Morimoto, Nobuki Tezuka, Satoshi Sugimoto

MATERIALS TRANSACTIONS　52　(4)　740-745　2011/04

DOI： 10.2320/matertrans.MBW201013 　

ISSN： 1345-9678

eISSN： 1347-5320
Magnetoresistance effect of tunnel junctions using Co-2(Ti, Mn)Z (Z = Al, Si) Heusler alloys Peer-reviewed

A. Sasaki, N. Tezuka, L. Jiang, S. Sugimoto

JOURNAL OF APPLIED PHYSICS　109　(7)　07C736　2011/04

DOI： 10.1063/1.3556778 　

ISSN： 0021-8979

eISSN： 1089-7550
Magnetic Properties of Nanoparticle-Polymer Composites Prepared Using Surface Modification and Cross-Linking Reaction Peer-reviewed

Kazuaki Shimba, Kiyotaka Furuta, Nobuyuki Morimoto, Nobuki Tezuka, Satoshi Sugimoto

MATERIALS TRANSACTIONS　52　(3)　486-490　2011/03

DOI： 10.2320/matertrans.MAW201020 　

ISSN： 1345-9678

eISSN： 1347-5320
Structural and magnetic properties of Co2FeAl 0.5Si0.5 full-Heusler alloy thin films deposited on Si substrates by molecular beam epitaxy Peer-reviewed

Tatsuya Saito, Ken Kano, Nobuki Tezuka, Satoshi Sugimoto

Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals　75　(3)　141-145　2011/03

DOI： 10.2320/jinstmet.75.141 　

ISSN： 0021-4876
Structural and Magnetic Properties of Co2FeAl0.5Si0.5 Full-Heusler Alloy Thin Films on GaAs Substrates Peer-reviewed

Tatsuya Saito, Nobuki Tezuka, Satoshi Sugimoto

MATERIALS TRANSACTIONS　52　(3)　370-373　2011/03

DOI： 10.2320/matertrans.MBW201004 　

ISSN： 1345-9678

eISSN： 1347-5320
Structural and Magnetic Properties of Co2FeAl0.5Si0.5 Full-Heusler Alloy Thin Films Deposited on Si Substrates by Molecular Beam Epitaxy Peer-reviewed

Tatsuya Saito, Ken Kano, Nobuki Tezuka, Satoshi Sugimoto

JOURNAL OF THE JAPAN INSTITUTE OF METALS　75　(3)　141-145　2011/03

DOI： 10.2320/jinstmet.75.141 　

ISSN： 0021-4876

eISSN： 1880-6880
Magnetoresistance Effect through GaAs for Fe/MgO/GaAs/MgO/Fe Junctions Peer-reviewed

N. Tezuka, F. Mitsuhashi, S. Sugimoto

2ND INTERNATIONAL SYMPOSIUM ON ADVANCED MAGNETIC MATERIALS AND APPLICATIONS (ISAMMA 2010)　266　2011

DOI： 10.1088/1742-6596/266/1/012109 　

ISSN： 1742-6588
Preparation and magnetic properties of amorphous Co-Fe-B nanoparticles Peer-reviewed

Kazuaki Shimba, Nobuki Tezuka, Satoshi Sugimoto

Journal of Physics: Conference Series　266　012044-012044-4　2011/01

DOI： 10.1088/1742-6596/266/1/012044 　
Nd-Fe-B sintered magnets fabrication by using atomized powders Peer-reviewed

Ryota Goto, Satoshi Sugimoto, Masashi Matsuura, Nobuki Tezuka, Yasuhiro Une, Masato Sagawa

Journal of Physics; Conference Series　266　012029　2011/01

DOI： 10.1088/1742-6596/266/1/012029 　
Influence of microstructural change of the interface between Nd₂Fe₁₄B and Nd-O phases on coercivity of Nd-Fe-B films by oxidation and subsequent low-temperature annealing

Masashi Matsuura, Ryota Goto, Nobuki Tezuka, Satoshi Sugimoto

Journal of Physics; Conference Series　266　012039　2011/01

DOI： 10.1088/1742-6596/266/1/012039 　
Spin injection and detection between CoFe/AlOx junctions and SOI investigates by Hanle effect measurements Peer-reviewed

TTT

JOURNAL OF THE JAPAN INSTITUTE OF METALSfff　75　141-145　2011
Influence of Nd Oxide Phase on the Coercivity of Nd-Fe-B Thin Films Peer-reviewed

Masashi Matsuura, Ryota Goto, Nobuki Tezuka, Satoshi Sugimoto

MATERIALS TRANSACTIONS　51　(10)　1901-1904　2010/10

DOI： 10.2320/matertrans.MAW201019 　

ISSN： 1345-9678

eISSN： 1347-5320
Preparation of composite nanoparticles based on cobalt ferrite Peer-reviewed

Nana Fukamachi, Nobuki Tezuka, Satoshi Sugimoto

Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals　74　(6)　345-350　2010/06

DOI： 10.2320/jinstmet.74.345 　

ISSN： 0021-4876
Preparation of Iron Nitride Fe16N2 Nanoparticles by Reduction of Iron Nitrate Peer-reviewed

Kazuaki Shimba, Nobuki Tezuka, Satoshi Sugimoto

JOURNAL OF THE JAPAN INSTITUTE OF METALS　74　(3)　209-213　2010/03

DOI： 10.2320/jinstmet.74.209 　

ISSN： 0021-4876

eISSN： 1880-6880
Microstructure During the Fabrication Process of Nd-Fe-B Sintered Magnets Using Atomized Powders

Ryota Goto, Satoshi Sugimoto, Masashi Matsuura, Nobuki Tezuka, Yasuhiro Une, Masato Sagawa

Proceeding of the 21st Workshop on Rare-Earth Permanent Magnets and their applications (REPM' 10), Bled, Slovenia, 29 Augast -2 September 2010　193-196　2010
Influence of Nd₂Fe₁₄B/Nd(-O) Interfacial Microstructure on Coercivity in Nd-Fe-B Thin Films

Masashi Matsuura, Satoshi Sugimoto, Ryota Goto, Nobuki Tezuka

Proceeding of the 21st Workshop on Rare-Earth Permanent Magnets and their applications (REPM' 10), Bled, Slovenia, 29 Augast -2 September 2010　317-319　2010
Preparation of Composite Nanoparticles Based on Cobalt Ferrite

Nana Fukamachi, Nobuki Tezuka, Sugimoto Sugimoto

Journal of the JAPAN Institute of METALS　74　745-750　2010
表面修飾された磁性ナノ粒子によるナノコンポジット粉末の作製 Peer-reviewed

榛葉和晃, 深町七奈, 手束展規, 杉本諭

電気学会研究会資料 MAGマグネティックス研究会　71　(71)　7-12　2010
Influence of Oxidation and Cu Addition on Coercivity of Nd-Fe-B Thin Films

Masashi Matsuura, Togo Fukada, Ryota Goto, Nobuki Tezuka, Satoshi Sugimoto

The Papers of Technical Meeting on Magnetics, IEE Japan　MAG-09-184　77-81　2009/12/01
Microstructural Evaluation of Nd-Fe-B Jet-Milled Powders Peer-reviewed

Takashi Hattori, Hiroki Ishihara, Satoshi Sugimoto, Ryota Goto, Nobuki Tezuka, Yasuhiro Une, Masato Sagawa

MATERIALS TRANSACTIONS　50　(10)　2347-2350　2009/10

DOI： 10.2320/matertrans.MAW200915 　

ISSN： 1345-9678

eISSN： 1347-5320
Magnetoresistance Effect of Magnetic Tunnel Junction with Co2Ti0.5Mn0.5Al Full-Heusler Alloy Thin Film Peer-reviewed

Akihiro Sasaki, Nobuki Tezuka, Satoshi Sugimoto, Akinari Okubo, Rie Umetsu, Ryosuke Kainuma

JOURNAL OF THE JAPAN INSTITUTE OF METALS　73　(9)　670-673　2009/09

DOI： 10.2320/jinstmet.73.670 　

ISSN： 0021-4876

eISSN： 1880-6880
Influences of Oxidation State of Nd-Rich Phase on the Coercivity of Nd-Fe-B/Nd Thin Films Peer-reviewed

Masashi Matsuura, Togo Fukada, Ryota Goto, Nobuki Tezuka, Satoshi Sugimoto

MATERIALS TRANSACTIONS　50　(9)　2139-2142　2009/09

DOI： 10.2320/matertrans.MAW200913 　

ISSN： 1345-9678

eISSN： 1347-5320
Nd-Fe-B/Nd薄膜における酸化状態と保磁力

松浦昌志, 深田東吾, 後藤龍太, 手束展規, 杉本諭

電気学会マグネティックス研究会資料　MAG-09-71　50-53　2009/08/05
Coフェライト系ナノコンポジット粉末の磁気特性

深町七奈, 手束展規, 杉本諭

電気学会マグネティックス研究会資料　MAG-09-71　65-68　2009/08
Effect of Cu Addition on the Phase Equilibria in Nd-Fe-B Sintered Magnets Peer-reviewed

Shota Nishio, Satoshi Sugimoto, Ryota Goto, Masashi Matsuura, Nobuki Tezuka

MATERIALS TRANSACTIONS　50　(4)　723-726　2009/04

DOI： 10.2320/matertrans.MBW200824 　

ISSN： 1345-9678

eISSN： 1347-5320
Interfacial state and magnetic properties of Nd-Fe-B/Nd thin films Peer-reviewed

Masashi Matsuura, Satoshi Sugimoto, Ryota Goto, Nobuki Tezuka

JOURNAL OF APPLIED PHYSICS　105　(7)　07A741-1-07A741-3　2009/04

DOI： 10.1063/1.3076050 　

ISSN： 0021-8979
Tunnel magnetoresistance for magnetic tunnel junctions with Co2FeAl0.5Si0.5 full Heusler electrodes fabricated by molecular beam epitaxy system Peer-reviewed

N. Tezuka, N. Ikeda, F. Mitsuhashi, S. Sugimoto

JOURNAL OF APPLIED PHYSICS　105　(7)　07C925-1-07C925-3　2009/04

DOI： 10.1063/1.3072448 　

ISSN： 0021-8979

eISSN： 1089-7550
The Magnetoresistance of Fe/MgO/GaAs/MgO/Fe Junctions Peer-reviewed

Fuminori Mitsuhash, Nobuki Tezuka, Satoshi Sugimoto

JOURNAL OF THE JAPAN INSTITUTE OF METALS　73　(4)　251-254　2009/04

DOI： 10.2320/jinstmet.73.251 　

ISSN： 0021-4876

eISSN： 1880-6880
Improved tunnel magnetoresistance of magnetic tunnel junctions with Heusler Co2FeAl0.5Si0.5 electrodes fabricated by molecular beam epitaxy Peer-reviewed

N. Tezuka, N. Ikeda, F. Mitsuhashi, S. Sugimoto

APPLIED PHYSICS LETTERS　94　(16)　162504-1-162504-3　2009/04

DOI： 10.1063/1.3116717 　

ISSN： 0003-6951
High Frequency Magnetic Properties of Fe/Y₂O₃ Films Prepared by Aerosol Deposition Method Peer-reviewed

A. Sakaki, N. Tezuka, S. Sugimoto

Journal of the Magnetics Society of Japan　33　(3)　252-253　2009/03

DOI： 10.3379/msjmag.0903RD8076 　
Microstructural Evaluation of Nd-Fe-B Strip Cast Alloys Peer-reviewed

Takashi Hattori, Nana Fukamachi, Ryota Goto, Nobuki Tezuka, Satoshi Sugimoto

MATERIALS TRANSACTIONS　50　(3)　479-482　2009/03

DOI： 10.2320/matertrans.MBW200821 　

ISSN： 1345-9678

eISSN： 1347-5320
Temperature and Bias Voltage Dependence of Tunnel Magnetoresistance Effect in Magnetic Tunnel Junctions with Co₂Fe(Al,Si) Electrodes Fabricated by MBE Peer-reviewed

N. Tezuka, T. Saito, K. Kikuchi, A. Sasaki, F. Mitsuhashi, N. Ikeda, S.Sugimoto, T. Takenaga

Journal of Physics: conference series　2009

DOI： 10.1088/1742-6596/200/5/052028 　
Effect of Cu Addition on Coercivity and Interfacial State of Nd-Fe-B/Nd-rich Thin Films Peer-reviewed

Masashi Matsuura, Togo Fukada, Ryota Goto, Nobuki Tezuka, Satoshi Sugimoto

Jornal of Physics, Conference Series. 200　082019　2009

DOI： 10.1088/1742-6596/200/8/082019 　
Wettability between Nd2Fe14B and Nd-Rich Phase in Nd-Fe-B Alloy System Peer-reviewed

Shota Nishio, Ryota Goto, Masashi Matsuura, Nobuki Tezuka, Satoshi Sugimoto

JOURNAL OF THE JAPAN INSTITUTE OF METALS　72　(12)　1010-1014　2008/12

DOI： 10.2320/jinstmet.72.1010 　

ISSN： 0021-4876

eISSN： 1880-6880
Wettability and Interfacial Microstructure Between Nd2Fe14B and Nd-Rich Phases in Nd-Fe-B Alloys Peer-reviewed

Ryota Goto, Shota Nishio, Masashi Matsuura, Nobuki Tezuka, Satoshi Sugimoto

IEEE TRANSACTIONS ON MAGNETICS　44　(11)　4232-4234　2008/11

DOI： 10.1109/TMAG.2008.2001544 　

ISSN： 0018-9464
Search for new superconductors by the Li-intercalation into layered perovskites of the Aurivillius phase Peer-reviewed

Tezuka, H. Kato, M. Kajita, T. Noji, T. Koike

Physica C　468　(15-20)　1152-1154　2008/09/15

DOI： 10.1016/j.physc.2008.05.020 　
Influence of Dy addition on wettability between Nd₂Fe₁₄B and Nd-rich phases in Nd-Fe-B alloys Invited

R. Goto, S. Nishio, M. Matsuura, S. Sugimoto, N. Tezuka

Proceedings of 20th International Workshop on Rare Earth Permanent Magnet and Their Applications　118-121　2008/09/08
Site disorder in Co2Fe(Al,Si) Heusler alloys and its influence on junction tunnel magnetoresistance Peer-reviewed

K. Inomata, M. Wojcik, E. Jedryka, N. Ikeda, N. Tezuka

PHYSICAL REVIEW B　77　(21)　214425-1-214425-9　2008/06

DOI： 10.1103/PhysRevB.77.214425 　

ISSN： 2469-9950

eISSN： 2469-9969
Energy barrier and reversal mechanism in Co/Pt multilayer nanodot Peer-reviewed

S. Okamoto, T. Kato, N. Kikuchi, O. Kitakami, N. Tezuka, S. Sugimoto

JOURNAL OF APPLIED PHYSICS　103　(7)　07C501-1-07C501-3　2008/04

DOI： 10.1063/1.2831785 　

ISSN： 0021-8979
Magnetization reversal process and bistability of Co/Pt multilayer dot Peer-reviewed

N. Kikuchi, T. Kato, S. Okamoto, O. Kitakami, N. Tezuka, S. Sugimoto

JOURNAL OF APPLIED PHYSICS　103　(7)　07C510-1-07C510-3　2008/04

DOI： 10.1063/1.2838288 　

ISSN： 0021-8979
Enhanced tunnel magnetoresistance due to spin dependent quantum well resonance in specific symmetry states of an ultrathin ferromagnetic electrode Peer-reviewed

Tomohiko Niizeki, Nobuki Tezuka, Koichiro Inomata

PHYSICAL REVIEW LETTERS　100　(4)　047207-1-047207-4　2008/02

DOI： 10.1103/PhysRevLett.100.047207 　

ISSN： 0031-9007

eISSN： 1079-7114
Effect of Cu addition on the phase equilibria in Nd-Fe-B sintered magnets Peer-reviewed

R. Goto, S. Nishio, M. Matsuura, N. Tezuka, S. Sugimoto

IEEE Trans. Magn.　44　4232-4234　2008
Highly spin-polarized materials and devices for spintronics Peer-reviewed

Koichiro Inomata, Naomichi Ikeda, Nobuki Tezuka, Ryogo Goto, Satoshi Sugimoto, Marek Wojcik, Eva Jedryka

SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS　9　(1)　014101　2008/01

DOI： 10.1088/1468-6996/9/1/014101 　

ISSN： 1468-6996

eISSN： 1878-5514
Preparation of Fe/Oxide Composite Films by Aerosol Deposition Method

Masumi Noguchi, Shingo Mineta, Nobuki Tezuka, Satoshi Sugimoto, Jun Akedo

The Papers of Technical Meeting on Magnetics, IEE Japan　MAG-07-74　15-18　2007/07/24
Crystal structure and magnetic properties for a Co2FeAl1-xSix full-Heusler alloy thin film

Naomichi Ikeda, Nobuki Tezuka, Satoshi Sugimoto

The Papers of Technical Meeting on Magnetics, IEE Japan　MAG-07-73　11-14　2007/07/24
Fabrication and characterization of Co-ferrite thin films for a ferromagnetic barrier in a spin-filtering device operating at room temperature Peer-reviewed

R. Goto, Y. K. Takahashi, N. Tezuka, K. Inomata, S. Sugimoto, K. Hono

IEEE TRANSACTIONS ON MAGNETICS　43　(6)　2797-2799　2007/06

DOI： 10.1109/TMAG.2007.893696 　

ISSN： 0018-9464
Transmission electron microscopy of Co-2(Cr1-xFex)Al sputtered films and their magnetic tunneling junctions Peer-reviewed

Y. K. Takahashi, T. Ohkubo, K. Hono, S. Okamura, N. Tezuka, K. Inomata

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS　313　(2)　378-382　2007/06

DOI： 10.1016/j.jmmm.2006.09.023 　

ISSN： 0304-8853
Giant tunnel magnetoresistance at room temperature for junctions using full-heusler Co2FeAl0.5Si0.5 electrodes Peer-reviewed

Nobuki Tezuka, Naomichi Ikeda, Satoshi Sugimoto, Koichiro Inomata

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS　46　(17-19)　L454-L456　2007/05

DOI： 10.1143/JJAP.46.L454 　

ISSN： 0021-4922
Tunnel magnetoresistance in magnetic tunnel junctions with Co2Fe (Al, Si) full-Heusler films Peer-reviewed

N. Tezuka, N. Ikeda, A. Miyazaki, S. Okamura, M. Kikuchi, S. Sugimoto, K. Inomata

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS　310　(2)　1940-1942　2007/03

DOI： 10.1016/j.jmmm.2006.10.812 　

ISSN： 0304-8853
Preparation of Fe/Ni-Zn-Cu ferrite stacked films by aerosol deposition method Peer-reviewed

S. Sugimoto, V. Chan, M. Noguchi, N. Tezuka, K. Inomata, J. Akedo

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS　310　(2)　2549-2551　2007/03

DOI： 10.1016/j.jmmm.2006.11.146 　

ISSN： 0304-8853
Structural, magnetic and barrier properties for co-ferrite thin films fabricated by plasma oxidization Peer-reviewed

Ryota Goto, Yukiko Takahashi, Nobuki Tezuka, Koichiro Inomata, Satoshi Sugimoto, Kazuhiro Hono

JOURNAL OF THE JAPAN INSTITUTE OF METALS　71　(2)　258-262　2007/02

ISSN： 0021-4876

eISSN： 1880-6880
Structural, magnetic and barrier properties for Co-ferrite thin films fabricated by plasma oxidization Peer-reviewed

Ryota Goto, Yukiko Takahashi, Nobuki Tezuka, Koichiro Inomata, Satoshi Sugimoto, Kazuhiro Hono

Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals　71　(2)　258-262　2007/02

DOI： 10.2320/jinstmet.71.258 　

ISSN： 0021-4876
Coercivity and microstructure of Mn-Ni-N sintered alloys Invited Peer-reviewed

S. Sugimoto, K. Isogai, T. Hattori, H. Matsumoto, S. Yoshida, N. Tezuka

PHYSICA STATUS SOLIDI C - CURRENT TOPICS IN SOLID STATE PHYSICS, VOL 4, NO 12　4　(12)　4573-+　2007

DOI： 10.1002/psse.200777401 　

ISSN： 1862-6351
プラズマ酸化法により作製したCoフェライト薄膜の構造と磁気特性 Peer-reviewed

後藤龍太, 高橋有紀子, 中村新一, 手束展規, 猪俣浩一郎, 杉本諭, 宝野和博

日本応用磁気学会誌　31　(4)　351-355　2007
Publisher: The Magnetics Society of Japan
DOI： 10.3379/jmsjmag.31.351 　

ISSN： 0285-0192

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For the development of room temperature spin-filtering devices with a ferromagnetic barrier, very thin ferromagnetic barrier films were required. Co-ferrite thin films are prepared by the surface plasma oxidization of a CoFe₂ underlayer deposited on MgO (001) single crystal substrates. During oxidization, the substrate temperature was varied from 523 K to 673 K. The plasma oxidized CoFe₂ films had a spinel structure, 4-fold symmetry in the plane, and an epitaxial relationship with the CoFe₂ underlayer. The lattice parameter of Co-ferrite thin film was 0.828 nm, which is 1.2% less than that of bulk. The interface between the CoFe₂ and its oxide was relatively smooth. When the substrate temperature during plasma oxidization was lower than 623 K, magnetization of CoFe₂ and Co-ferrite rotated independently. XPS and MOKE measurements identified that the hard and soft phases as Co-ferrite and CoFe₂, respectively. Measurements of the magnetic properties showed that the magnetization of the Co-ferrite thin films was about 1100 emu/cm³, which is 2.6 times more than that of bulk (420 emu/cm³). This phenomenon may be explained by the exchange of Co and Fe cation distribution in our Co-ferrite films.
175% tunnel magnetoresistance at room temperature and high thermal stability using Co2FeAl0.5Si0.5 full-Heusler alloy electrodes Peer-reviewed

N. Tezuka, N. Ikeda, S. Sugimoto, K. Inomata

APPLIED PHYSICS LETTERS　89　(25)　2006/12

DOI： 10.1063/1.2420793 　

ISSN： 0003-6951
エアロゾル・デポジション法によるFe/NiZnCuフェライト複合膜の成膜過程

Masumi Noguchi, Shingo Mineta, Nobuki Tezuka, Satoshi Sugimoto, Jun Akedo

The papers of Joint Technical Meeting on Metal and Ceramics and Magnetics, IEE Japan　MC-06-9~16/MAG-06-159~166　11-15　2006/11/29
Permanent magnetic materials and spintronics Invited

TEZUKA Nobuki, SUGIMOTO Satoshi

KINZOKU (Materials Science & Technology)　76　(10)　57-61　2006/10/01
Current-driven resistance oscillation in exchange-biased spin valves with a low aspect ratio Peer-reviewed

Y. Jiang, N. Tezuka, K. Inomata

APPLIED PHYSICS LETTERS　89　(12)　122514-1-122514-3　2006/09

DOI： 10.1063/1.2356376 　

ISSN： 0003-6951
Tunnel magnetoresistance for junctions with epitaxial full-Heusler Co2FeAl0.5Si0.5 electrodes with B2 and L2(1) structures Peer-reviewed

N. Tezuka, N. Ikeda, A. Miyazaki, S. Sugimoto, M. Kikuchi, K. Inomata

APPLIED PHYSICS LETTERS　89　(11)　112514-1-112514-3　2006/09

DOI： 10.1063/1.2354026 　

ISSN： 0003-6951

eISSN： 1077-3118
Spin polarization of Co2FeSi full-Heusler alloy and tunneling magnetoresistance of its magnetic tunneling junctions Peer-reviewed

Z. Gercsi, A. Rajanikanth, Y. K. Takahashi, K. Hono, M. Kikuchi, N. Tezuka, K. Inomata

APPLIED PHYSICS LETTERS　89　(8)　082512-1-082512-3　2006/08

DOI： 10.1063/1.2338025 　

ISSN： 0003-6951

eISSN： 1077-3118
Indirect exchange spring between FePt and Fe with a Ru interlayer Peer-reviewed

J Jiang, N Tezuka, K Inomata

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS　302　(1)　40-46　2006/07

DOI： 10.1016/j.jmmm.2005.08.009 　

ISSN： 0304-8853
Structural dependence of the tunnel magnetoresistance for magnetic tunnel junctions with a full-Heusler Co2Fe(Al,Si) electrode Peer-reviewed

N. Tezuka, S. Okamura, A. Miyazaki, M. Kikuchi, K. Inomata

JOURNAL OF APPLIED PHYSICS　99　(8)　08T314 -1-08T314 -3　2006/04

DOI： 10.1063/1.2167069 　

ISSN： 0021-8979

eISSN： 1089-7550
Structural and magnetic properties and tunnel magnetoresistance for Co-2(Cr,Fe)Al and Co2FeSi full-Heusler alloys Peer-reviewed

K Inomata, S Okamura, A Miyazaki, M Kikuchi, N Tezuka, M Wojcik, E Jedryka

JOURNAL OF PHYSICS D-APPLIED PHYSICS　39　(5)　816-823　2006/03

DOI： 10.1088/0022-3727/39/5/S07 　

ISSN： 0022-3727

eISSN： 1361-6463
Epitaxial Growth of Ordered Co2(Cr1-xFex)Al Full-Heusler Alloy Films on Single Crystal Substrates Peer-reviewed

Susumu Okamura, Aya Miyazaki, Nobuki Tezuka, Satoshi Sugimoto, Koichiro Inomata

Materials Transactions　47　(1)　15-19　2006/01

DOI： 10.2320/matertrans.47.15 　
Quantum oscillation of the tunneling conductance in fully epitaxial double barrier magnetic tunnel junctions Peer-reviewed

T Nozaki, N Tezuka, K Inomata

PHYSICAL REVIEW LETTERS　96　(2)　027208-1-027208-4　2006/01

DOI： 10.1103/PhysRevLett.96.027208 　

ISSN： 0031-9007

eISSN： 1079-7114
ナノドットFe中間層を有するエピタキシャル強磁性２重トンネル接合におけるコンダクタンスの振動現象 Peer-reviewed

野崎隆行, 中村新一, 手束展規, 杉本諭, 猪俣浩一郎

日本応用磁気学会誌　30　(2)　180-183　2006
Publisher: The Magnetics Society of Japan
DOI： 10.3379/jmsjmag.30.180 　

ISSN： 0285-0192

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Double-barrier magnetic tunnel junctions (DMTJs) with an Fe(001) / MgO(001) / Fe(001) / MgO(001) / Fe(001) structure were deposited upon MgO(001) substrates by using molecular beam epitaxy. The DMTJs were found to show the TMR ratio of up to 110% and an extremely small bias voltage dependence (V_1/2 = 1.4 V under a positive bias application) at room temperature. We also investigated the middle-layer thickness dependence of the conductance curve in the DMTJs. Clear oscillations of the conductance were observed in a parallel magnetization configuration. This oscillation is thought to originate in the modulation of the tunneling conductance by the spin-polarized quantum well states created in the middle Fe layer.
MgO基板上に作製したCo2V0.67Fe0.33Al薄膜の構造と磁性およびトンネル磁気抵抗 Peer-reviewed

宮崎彩, 岡村進, 杉本諭, 手束展規, 猪俣浩一郎

日本応用磁気学会誌　30　(3)　378-382　2006
Publisher: The Magnetics Society of Japan
DOI： 10.3379/jmsjmag.30.378 　

ISSN： 0285-0192

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Co₂V_0.67Fe_0.33Al full-Heulser alloy films were fabricated on an MgO (100) single crystalline substrate by using two different heat treatments: substrate heating and post-annealing. Ultra-high-vacuum dc magnetron sputtering was used to prepare the sample. The L2₁ structure was obtained when the substrate temperature (T_s) was 500°C. For the same sample, the magnetic moment per formula unit showed the highest value of 2.4 μB at 5 K. There were small differences between the samples fabricated by substrate heating and post-annealing in terms of their structural and magnetic properties. A magnetic tunnel junction (MTJ) using Co₂V_0.67Fe_0.33Al as a bottom electrode was fabricated. A larger tunnel magnetoresistance (TMR) was obtained by substrate heating than post-annealing with a maximum value of 28% at RT and 50% at 5 K when the Co₂V_0.67Fe_0.33Al was sputtered at T_s = 500°C. We found that there is an intimate relationship between the lattice constant of Co₂V_0.67Fe_0.33Al and the TMR.
不規則構造を有するCo2(Cr1-xFex)Alを用いた強磁性トンネル接合のTMR特性 Peer-reviewed

岡村進, 宮崎彩, 手束展規, 杉本諭, 猪俣浩一郎, 高橋有紀子, 宝野和博

日本応用磁気学会誌　30　(3)　366-369　2006
Publisher: The Magnetics Society of Japan
DOI： 10.3379/jmsjmag.30.366 　

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Polycrystalline and single crystalline thin films of Co₂(Cr_1-xFe_x)Al (x = 0.6, 1) full-Heusler alloys with different disordering were prepared on thermally oxidized Si and MgO(001) substrates, respectively, by the dc magnetron sputtering method. The magnetic tunnel junctions with a polycrystalline and single crystalline B2 type Co₂FeAl (x =1) electrode demonstrate TMR of 70% and 75% at 5 K, respectively, which is larger than that of 65% at 5 K for Co₇₅Fe₂₅, indicating that the spin polarization for Co₂FeAl is larger than that for Co₇₅Fe₂₅. The TMR for Co₂FeAl with both the A2 and the B2, which is controlled by substrate heating, is almost the same, whereas for Co₂(Cr_0.4Fe_0.6)Al the TMR increases with increasing the degree of ordering, corresponding to the first-principles calculations.
Tunnel magnetoresistance for magnetic tunnel junctions with a disordered Co 2(Cr 1-xFe x)Al full-heusler alloy electrode Peer-reviewed

Susumu Okamura, Aya Miyazaki, Nobuki Tezuka, Koichiro Inomata

IEEJ Transactions on Fundamentals and Materials　126　(5)　276-280　2006

DOI： 10.1541/ieejfms.126.276 　

ISSN： 0385-4205 1347-5533
エアロゾル・デポジッション法により作製したFe/Ni-Zn-Cuフェライト複合膜における組成制御と電磁ノイズ抑制効果 Peer-reviewed

チャンビサル, 杉本諭, 猪俣浩一郎, 手束展規, 明度純

日本応用磁気学会誌　30　(5)　505-509　2006
Publisher: The Magnetics Society of Japan
DOI： 10.3379/jmsjmag.30.505 　

ISSN： 0285-0192
L21構造を持つCo2CrGaフルホイスラー合金薄膜の作製とそれを用いた強磁性トンネル接合素子のトンネル磁気抵抗 Peer-reviewed

正木達章, 菊地麻樹, 手束展規, 杉本諭, 猪俣浩一郎, 貝沼亮介, 石田清仁

日本応用磁気学会誌　30　(4)　455-458　2006
Publisher: The Magnetics Society of Japan
DOI： 10.3379/jmsjmag.30.455 　

ISSN： 0285-0192

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We have investigated that the structural and magnetic properties of Co₂CrGa full-Heusler alloy films and researched the tunnel magnetoresistance (TMR) in magnetic tunnel junctions (MTJs) using a Co₂CrGa electrode on a MgO(100) substrate. Co₂CrGa films were fabricated with substrate heating (RT ≤ T_s ≤ 500°C) or post-annealing (RT ≤ T_a ≤ 500°C) after the deposition using an ultrahigh vacuum dc magnetron sputtering system. L2₁-ordered Co₂CrGa thin films were obtained at T_s ≥ 300°C or T_a ≥ 200°C. The maximum magnetic moment per formula unit measured at 5 K were 2.8 μ_B and 2.6 μ_B for T_S and T_a = 400°C, respectively, which are over 85% of the theoretical value. The maximum TMR of 18% at RT and 42% at 5 K are obtained for the MTJ using the L2₁-structured Co₂CrGa film as a bottom electrode. It is expected that the TMR can be enhanced by optimizing the interface of Co₂CrGa/AlOx.
Magnetic properties of epitaxial Co2Cr1-xFexAl full Heusler alloy thin films with the L2(1) structure Peer-reviewed

A Hirohata, H Kurebayashi, S Okamura, N Tezuka, K Inomata

IEEE TRANSACTIONS ON MAGNETICS　41　(10)　2802-2804　2005/10

DOI： 10.1109/TMAG.2005.854831 　

ISSN： 0018-9464

eISSN： 1941-0069
Magnetic transport mechanism in double ferromagnetic tunnel junctions with two-dimensional ferromagnetic particles Peer-reviewed

H Sukegawa, A Hirohata, S Nakamura, N Tezuka, S Sugimoto, K Inomata

IEEE TRANSACTIONS ON MAGNETICS　41　(10)　2679-2681　2005/10

DOI： 10.1109/TMAG.2005.855292 　

ISSN： 0018-9464
Exchange coupling between FePt and Fe through Ru interlayer Peer-reviewed

JH Jiang, N Tezuka, K Inomata

JOURNAL OF APPLIED PHYSICS　98　(6)　063902-1-063902-3　2005/09

DOI： 10.1063/1.2058189 　

ISSN： 0021-8979
Large tunnel magnetoresistance at room temperature with a Co2FeAl full-Heusler alloy electrode Peer-reviewed

S Okamura, A Miyazaki, S Sugimoto, N Tezuka, K Inomata

APPLIED PHYSICS LETTERS　86　(23)　232503-1-232503-3　2005/06

DOI： 10.1063/1.1944893 　

ISSN： 0003-6951

eISSN： 1077-3118
Distinctive current-induced magnetization switching in a current-perpendicular-to-plane giant-magnetoresistance nanopillar with a synthetic antiferromagnet free layer Peer-reviewed

T Ochiai, Y Jiang, A Hirohata, N Tezuka, S Sugimoto, K Inomata

APPLIED PHYSICS LETTERS　86　(24)　242506-1-242506-3　2005/06

DOI： 10.1063/1.1949709 　

ISSN： 0003-6951

eISSN： 1077-3118
Structural and magnetic properties of epitaxial L2(1)-structured Co-2(CrFe)Al films grown on GaAs(001) substrates Peer-reviewed

A Hirohata, H Kurebayashi, S Okamura, M Kikuchi, T Masaki, T Nozaki, N Tezuka, K Inomata

JOURNAL OF APPLIED PHYSICS　97　(10)　103714-1-103714-8　2005/05

DOI： 10.1063/1.1888050 　

ISSN： 0021-8979

eISSN： 1089-7550
Spin transfer in antisymmetric exchange-biased spin-valves Peer-reviewed

Y Jiang, GH Yu, YB Wang, J Teng, T Ochiai, N Tezuka, K Inomata

APPLIED PHYSICS LETTERS　86　(19)　192515-1-192515-3　2005/05

DOI： 10.1063/1.1927694 　

ISSN： 0003-6951
Structural and magnetic properties of epitaxial L2(1)-structured Co-2(CrFe)Al films grown on GaAs(001) substrates Peer-reviewed

A Hirohata, H Kurebayashi, S Okamura, M Kikuchi, T Masaki, T Nozaki, N Tezuka, K Inomata

JOURNAL OF APPLIED PHYSICS　97　(10)　10C308-1-10C308-3　2005/05

DOI： 10.1063/1.1888050 　

ISSN： 0021-8979

eISSN： 1089-7550
CPP-GMR enhancement in spin valves using a thin Ru layer Peer-reviewed

N Tezuka, S Abe, Y Jiang, K Inomata

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS　290　1150-1153　2005/04

DOI： 10.1016/j.jmmm.2004.11.499 　

ISSN： 0304-8853
Significant magnetoresistance enhancement due to a cotunneling process in a double tunnel junction with single discontinuous ferromagnetic layer insertion Peer-reviewed

H Sukegawa, S Nakamura, A Hirohata, N Tezuka, K Inomata

PHYSICAL REVIEW LETTERS　94　(6)　068304-1-068304-4　2005/02

DOI： 10.1103/PhysRevLett.94.068304 　

ISSN： 0031-9007
Bias voltage effect on tunnel magnetoresistance in fully epitaxial MgO double-barrier magnetic tunnel junctions Peer-reviewed

T Nozaki, A Hirohata, N Tezuka, S Sugimoto, K Inomata

APPLIED PHYSICS LETTERS　86　(8)　082501-1-082501-3　2005/02

DOI： 10.1063/1.1867559 　

ISSN： 0003-6951

eISSN： 1077-3118
A trial for fabricating a spin-filter operating at room temperature using a ferromagnetic insulator

R. Goto, N. Tezuka, S. Sugimoto, K. Inomata

INTERMAG ASIA 2005: Digests of the IEEE International Magnetics Conference　307　2005
Publisher: IEEE Computer Society
DOI： 10.1109/intmag.2005.1463735 　
Tunnel magnetoresistance in magnetic tunnel junctions with a disordered Co2(Cr1-xFex)Al full-Heusler alloy film

S. Okamura, A. Miyazaki, N. Tezuka, S. Sugimoto, K. Inomata

INTERMAG ASIA 2005: Digests of the IEEE International Magnetics Conference　993　2005
Half-metallic Heusler Alloy Thin Films and TMR for Their Magnetic Tunnel Junctions

Inomata Koichiro, Okamura Susumu, Tezuka Nobuki

Bulletin of the Japan Institute of Metals　44　(8)　654-660　2005
Publisher: The Japan Institute of Metals and Materials
DOI： 10.2320/materia.44.654 　

ISSN： 1340-2625
L21構造を有するCo2Cr1-xFexAl薄膜の結晶構造と磁気特性 Peer-reviewed

廣畑貴文, 紅林秀和, 岡村進, 菊地麻樹, 正木達章, 野崎隆行, 手束展規, 猪俣浩一郎

日本応用磁気学会誌　29　(2)　124-127　2005
Publisher: The Magnetics Society of Japan
DOI： 10.3379/jmsjmag.29.124 　

ISSN： 0285-0192

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We successfully grew Co₂Cr_1-xFe_xAl full Heusler films (0 ≤ x ≤ 1) with the L2₁ structure onto GaAs(001) substrates by achieving stoichiometry in an ultrahigh-vacuum molecular beam epitaxy chamber. The films develop epitaxial crystallinity with the relationship of Co₂Cr_1-xFe_xAl(001)‹110›||GaAs(001)‹110›, which induces very strong uniaxial magnetocrystalline anisotropy, except for x = 0. For x = 1, in particular, the film is almost a single phase and its magnetic moment per formula unit exhibits Slater-Pauling behavior. Films of this type were used to fabricate magnetic tunnel junctions with 8.8% and 4.9% tunnel magnetoresistance (TMR) ratios at room temperature for x = 1 with an Al-O tunnel barrier and x = 0.6 with a MgO barrier, respectively. The TMR ratio can be further enhanced by both realizing an L2₁ single phase and eliminating lattice distortion.
強磁性ナノドット層を有する二重トンネル接合におけるTMRの増大 Peer-reviewed

介川裕章, 中村新一, 廣畑貴文, 手束展規, 猪俣浩一郎, 杉本諭

日本応用磁気学会誌　29　(3)　274-277　2005
Publisher: The Magnetics Society of Japan
DOI： 10.3379/jmsjmag.29.274 　

ISSN： 0285-0192

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We observed spin-dependent tunneling in Co₉₀Fe₁₀/AlO_x/Co₉₀Fe₁₀/AlO_x/Co₉₀Fe₁₀ ferromagnetic double tunnel junctions. A middle Co₉₀Fe₁₀ layer, which is inserted between two AlO_x layers, is discontinuous due to the difference in the surface energy of these layers. The average diameter of Co₉₀Fe₁₀ particles was estimated to be 2.0-4.5 nm from cross-sectional transmission electron microscopy (TEM) images. At low temperature (< 50 K), a Coulomb gap is observed in current-voltage (I-V) curves, and the tunnel magnetoresistance (TMR) ratio within the gap enhances significantly with decreasing temperature, which indicates that the dominant electron transport is inelastic co-tunneling within the Coulomb gap. These observations in a ferromagnetic tunnel junction with 2-dimensional magnetic nano-particle layer insertion accord well with theoretical predictions by Takahashi and Maekawa [Phys. Rev. Lett. 80, 1758 (1998)].
Co2CrGaフルホイスラー合金薄膜の結晶構造と磁気・電気伝導特性 Peer-reviewed

菊地麻樹, 正木達章, 手束展規, 杉本諭, 猪俣浩一郎

日本応用磁気学会誌　29　(4)　455-458　2005
Publisher: The Magnetics Society of Japan
DOI： 10.3379/jmsjmag.29.455 　

ISSN： 0285-0192

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We investigated the structural, magnetic and electrical transport properties of Co₂CrGa full Heusler alloy films, and optimized the growth conditions, achieving stoichiometric films. The crystalline structures and the magnetic and electrical transport properties were found to depend on the film thickness, t_CCG. An ordered L2₁ structure was obtained for t_CCG≥100 nm. The saturation magnetization decreases with decreasing film thickness and vanishes below t_CCG=23 nm, indicating the existence of a magnetically dead layer in the vicinity of the substrates. For t_CCG=150 nm, the saturation magnetization is 602 emu/cm³ (3.1 μ_B) at 5 K, which agrees very well with the theoretical value. The resistivity of the samples with t_CCG≤150 nm decreases with increasing temperature, while that with t_CCG=300 nm increases. By using films with t_CCG=100 nm and 300 nm as bottom electrodes, forming an L2₁ structure, magnetic tunnel junctions (MTJs) were also fabricated, showing 5.0% and 1.4% tunnel magnetoresistance (TMR) at RT, respectively.
Structural, magnetic, and transport properties of full-Heusler alloy Co-2(Cr1-xFex)Al thin films Peer-reviewed

S Okamura, R Goto, S Sugimoto, N Tezuka, K Inomata

JOURNAL OF APPLIED PHYSICS　96　(11)　6561-6564　2004/12

DOI： 10.1063/1.1810207 　

ISSN： 0021-8979
Spin-dependent quantum oscillations in magnetic tunnel junctions with Ru quantum wells Peer-reviewed

T. Nozaki, Y. Jiang, Y. Kaneko, A. Hirohata, N. Tezuka, S. Sugimoto, K. Inomata

Physical Review B - Condensed Matter and Materials Physics　70　(17)　1-4　2004/11

DOI： 10.1103/PhysRevB.70.172401 　

ISSN： 0163-1829
Tunnel magneto resistance using full-Heusler alloys Peer-reviewed

K Inomata, S Okamura, N Tezuka

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS　282　269-274　2004/11

DOI： 10.1016/j.jmmm.2004.04.063 　

ISSN： 0304-8853

eISSN： 1873-4766
Spin-dependent quantum oscillations in magnetic tunnel junctions with Ru quantum wells Peer-reviewed

T Nozaki, Y Jiang, Y Kaneko, A Hirohata, N Tezuka, S Sugimoto, K Inomata

PHYSICAL REVIEW B　70　(17)　172401-172401　2004/11

DOI： 10.1103/PhysRevB.70.172401 　

ISSN： 1098-0121
Effect of the soft/hard exchange interaction on natural resonance frequency and electromagnetic wave absorption of the rare earth-iron-boron compounds Peer-reviewed

T Maeda, S Sugimoto, T Kagotani, N Tezuka, K Inomata

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS　281　(2-3)　195-205　2004/10

DOI： 10.1016/j.jmmm.2004.04.105 　

ISSN： 0304-8853
Influence of synthetic antiferromagnet free layer on current-perpendicular-to-plane spin-valves Peer-reviewed

Y Jiang, S Abe, T Nozaki, N Tezuka, K Inomata

IEEE TRANSACTIONS ON MAGNETICS　40　(4)　2245-2247　2004/07

DOI： 10.1109/TMAG.2004.830231 　

ISSN： 0018-9464
Magnetoresistance in tunnel junctions using Co-2(Cr,Fe)Al full Heusler alloys Peer-reviewed

K Inomata, N Tezuka, S Okamura, H Kurebayashi, A Hirohata

JOURNAL OF APPLIED PHYSICS　95　(11)　7234-7236　2004/06

DOI： 10.1063/1.1651813 　

ISSN： 0021-8979

eISSN： 1089-7550
Substantial reduction of critical current for magnetization switching in an exchange-biased spin valve Peer-reviewed

Y Jiang, T Nozaki, S Abe, T Ochiai, A Hirohata, N Tezuka, K Inomata

NATURE MATERIALS　3　(6)　361-364　2004/06

DOI： 10.1038/nmat1120 　

ISSN： 1476-1122

eISSN： 1476-4660
Magnetic domain structures and switching properties in submicron size synthetic antiferromagnets Peer-reviewed

N. Tezuka, N. Koike, K. Sakurada, K. Inomata

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS　272　E1289-E1291　2004/05

DOI： 10.1016/j.jmmm.2003.12.403 　

ISSN： 0304-8853
Magnetic switching properties of magnetic tunnel junctions using a synthetic ferrimagnet free layer Peer-reviewed

T Nozaki, Y Jiang, H Sukegawa, N Tezuka, A Hirohata, K Inomata, S Sugimoto

JOURNAL OF APPLIED PHYSICS　95　(7)　3745-3748　2004/04

DOI： 10.1063/1.1669053 　

ISSN： 0021-8979
Effective reduction of critical current for current-induced magnetization switching by a Ru layer insertion in an exchange-biased spin valve Peer-reviewed

Y Jiang, S Abe, T Ochiai, T Nozaki, A Hirohata, N Tezuka, K Inomata

PHYSICAL REVIEW LETTERS　92　(16)　167204-1-167204-4　2004/04

DOI： 10.1103/PhysRevLett.92.167204 　

ISSN： 0031-9007
Magnetoresistance of magnetic double tunnel junctions Peer-reviewed

H Sukegawa, N Tezuka, K Inomata, S Sugimoto

JOURNAL OF THE JAPAN INSTITUTE OF METALS　68　(2)　74-77　2004/02

ISSN： 0021-4876

eISSN： 1880-6880
Magnetoresistance of magnetic tunnel junctions with Zn0.4Fe2.6O4 thin films Peer-reviewed

K Nishimura, N Tezuka, S Sugimoto, K Inomata

JOURNAL OF THE JAPAN INSTITUTE OF METALS　68　(2)　82-85　2004/02

ISSN： 0021-4876

eISSN： 1880-6880
Structural, magnetic and transport properties of CO2Cr1-xFexAl full-Heusler alloys Peer-reviewed

S Okamura, R Goto, N Tezuka, S Sugimoto, K Inomata

JOURNAL OF THE JAPAN INSTITUTE OF METALS　68　(2)　114-117　2004/02

DOI： 10.2320/jinstmet.68.114 　

ISSN： 0021-4876

eISSN： 1880-6880
Magnetoresistance of Magnetic Tunnel Junctions with Zn0.4Fe 2.6O4 Thin Films Peer-reviewed

Kazumasa Nishimura, Nobuki Tezuka, Satoshi Sugimoto, Koichiro Inomata

Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals　68　(2)　82-85　2004
Publisher: Japan Institute of Metals (JIM)
DOI： 10.2320/jinstmet.68.82 　

ISSN： 0021-4876
Magnetoresistance of Magnetic Double Tunnel Junctions Peer-reviewed

Hiroaki Sukegawa, Nobuki Tezuka, Koichiro Inomata, Satoshi Sugimoto

Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals　68　(2)　74-77　2004
Publisher: Japan Institute of Metals (JIM)
DOI： 10.2320/jinstmet.68.74 　

ISSN： 0021-4876
Co2(Cr1-xFex)Alフルホイスラー合金を用いたMTJの磁気抵抗効果 Peer-reviewed

岡村進, 後藤龍太, 手束展規, 杉本諭, 猪俣浩一郎

日本応用磁気学会誌　28　(2)　172-175　2004
Publisher: The Magnetics Society of Japan
DOI： 10.3379/jmsjmag.28.172 　

ISSN： 0285-0192

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Co₂CrAl (x = 0) films were found to form a B2 structure, and when Fe was substituted for Cr (x = 0.4−0.6), the films crystallized B2+A2 structures, while an A2 structure was stable in the case of Co₂FeAl (x = 1) films deposited on thermally oxidized Si substrates at room temperature. The magnetic moments of the films containing Fe tended to increase with increasing x, while those of the films containing Cr were far from the values calculated with an assumption of the L2₁ structure ordering.<BR>Spin-valve-type tunneling junctions with a Co₂(Cr_1-xFe_x) Al film were also fabricated, which demonstrated large tunneling magnetoresistance of 19.1% (x= 0.4) at room temperature and 27.2% at 5 K in spite of atomic site disorder.
極薄Ruキャップ層を用いたスピンバルブ素子のCPP-GMR特性 Peer-reviewed

阿部慎也, 山口正彦, 手束展規, 猪俣浩一郎

日本応用磁気学会誌　28　(9)　987-990　2004
Publisher: The Magnetics Society of Japan
DOI： 10.3379/jmsjmag.28.987 　

ISSN： 0285-0192

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We have studied the current-perpendicular-to-plane giant magnetoresistance (CPP-GMR) of single spin-valve (SV) films with two different free layers : one is a single ferromagnet layer (conventional), and the other is a ferromagnetic layer with a ruthenium cap layer (Ru cap). When the spacer Cu layer thickness is 2.5 nm and the Ru layer is 0.45 nm, the Ru cap-type greatly enhances the CPP-GMR, with increasing its value up to 4.3%. We argue that the MR enhancement is probably caused by the spin-dependent scattering due to the strong reflection of majority spins at the Co₉₀Fe₁₀/Ru interface.
Enhanced Current-perpendicular-to-plane Giant Magnetoresistance in Single Spin-valve with Synthetic Antiferromagnet Free Layers Peer-reviewed

Y. Jiang, S. Abe, T. Nozaki, N. Tezuka, K. Inomata

Transactions of the Materials Research Society of Japan　29　1531-1533　2004
Perpendicular giant magnetoresistance and magnetic switching properties of a single spin valve with a synthetic antiferromagnet as a free layer Peer-reviewed

Y Jiang, S Abe, T Nozaki, N Tezuka, K Inomata

PHYSICAL REVIEW B　68　(22)　224426-1-224426-7　2003/12

DOI： 10.1103/PhysRevB.68.224426 　

ISSN： 1098-0121
Enhancement of current-perpendicular-to-plane giant magnetoresistance by synthetic antiferromagnet free layers in single spin-valve films Peer-reviewed

Y Jiang, S Abe, T Nozaki, N Tezuka, K Inomata

APPLIED PHYSICS LETTERS　83　(14)　2874-2876　2003/10

DOI： 10.1063/1.1616974 　

ISSN： 0003-6951
Improved thermal stability of ferromagnetic tunnel junctions with a CoFe/CoFeOX/CoFe pinned layer Peer-reviewed

T Ochiai, N Tezuka, K Inomata, S Sugimoto, Y Saito

IEEE TRANSACTIONS ON MAGNETICS　39　(5)　2797-2799　2003/09

DOI： 10.1109/TMAG.2003.815715 　

ISSN： 0018-9464
Magnetization reversal and domain structure of antiferromagnetically coupled submicron elements Peer-reviewed

N Tezuka, N Koike, K Inomata, S Sugimoto

JOURNAL OF APPLIED PHYSICS　93　(10)　7441-7443　2003/05

DOI： 10.1063/1.1539074 　

ISSN： 0021-8979
Size-independent spin switching field using synthetic antiferromagnets Peer-reviewed

K Inomata, N Koike, T Nozaki, S Abe, N Tezuka

APPLIED PHYSICS LETTERS　82　(16)　2667-2669　2003/04

DOI： 10.1063/1.1568823 　

ISSN： 0003-6951
Large tunneling magnetoresistance at room temperature using a Heusler alloy with the B2 structure Peer-reviewed

K Inomata, S Okamura, R Goto, N Tezuka

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS　42　(4B)　L419-L422　2003/04

DOI： 10.1143/JJAP.42.L419 　

ISSN： 0021-4922
Application of Permanent Magnet Materials for Microwave Absorbers in the GHz Range

Satoshi Sugimoto, Toru Maeda, Toshio Kagotani, Nobuki Tezuka, Koichiro Inomata

Materia Japan　42　(3)　202-205　2003/02

DOI： 10.2320/materia.42.202 　
Perpendicular giant magnetoresistance and magnetic switching properties of a single spin valve with a synthetic antiferromagnet as a free layer Peer-reviewed

Y. Jiang, S. Abe, T. Nozaki, N. Tezuka, K. Inomata

Physical Review B - Condensed Matter and Materials Physics　68　(22)　2244261-2244267　2003

DOI： 10.1103/PhysRevB.68.224426 　

ISSN： 0163-1829
Natural Resonance Phenomena and GHz-range Microwave Absorption of the (Y_1-xSm_x)₂Fe₁₄B Compound Peer-reviewed

Toru Maeda, Nobuki Tezuka, Toshio Kagotani, Satoshi Sugimoto, Koichiro Inomata

Journal of the Japan Society of Powder and Powder Metallurgy　50　(1)　63-67　2003/01

DOI： 10.2497/jjspm.50.63 　
ZnxFe3-xO4薄膜の構造および磁気・電気特性 Peer-reviewed

西村和正, 手束展規, 猪俣浩一郎, 杉本諭

日本応用磁気学会誌　27　(4)　340-343　2003
Publisher: The Magnetics Society of Japan
DOI： 10.3379/jmsjmag.27.340 　

ISSN： 0285-0192

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The structural, magnetic, and electrical properties of sputtered Zn_xFe_3-xO₄ thin films were investigated. A spinel structure was obtained for samples annealed above 673 K. The magnetization at 10 kOe of a sample sputtered in Ar and annealed at 873 K was 450 emu/cm³. Magnetization decreased in samples annealed above 873 K, as a result of evaporation of Zn and an increase in the thickness of the insulating layer. A MR ratio of about 4.3 % was observed at T = 300 K in a sample sputtered in Ar and O₂ mixed gas, and MR curve was of a granular type. However, because the Zn was completely evaporated at this sample, the MR was associated with the Fe₃O₄ grains and the α-Fe₂O₃ boundary.
微細反平行結合素子の磁化状態とスピン反転磁場 Peer-reviewed

小池伸幸, 手束展規, 猪俣浩一郎, 杉本諭

日本応用磁気学会誌　27　(4)　316-319　2003
Publisher: The Magnetics Society of Japan
DOI： 10.3379/jmsjmag.27.316 　

ISSN： 0285-0192

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Arrays of synthetic antiferromagnetic (SyAF) patterned elements were successfully fabricated with micron to submicron sizes. Their magnetic domain structures and spin-switching fields were investigated by using magnetic force microscopy (MFM) and the magnetic optical Kerr effect (MOKE), respectively. A single-domain structure was observed in Co₉Fe/Ru/Co₉Fe SyAF bits for even a small aspect ratio of 1, while Co₉Fe monolayer bits showed a multi-domain structure for aspect ratios below 2. The spin-switching field of Co₉Fe (6 nm)/Ru (0.45 nm)/Co₉Fe (10 nm) SyAF exhibited independence of element size, while that of Co₉Fe (10 nm) single elements was strongly dependent on element size. These results indicate the predominance of SyAF for ultrahigh-bit-density MRAM devices.
ピン層にCoFe/CoFeOx/CoFeを用いた強磁性トンネル接合の耐熱性の改善 Peer-reviewed

落合隆夫, 手束展規, 猪俣浩一郎, 杉本諭, 斉藤好昭

日本応用磁気学会誌　27　(4)　307-310　2003
Publisher: The Magnetics Society of Japan
DOI： 10.3379/jmsjmag.27.307 　

ISSN： 0285-0192

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The annealing temperature dependence of the tunnel magnetoresistance (TMR) ratio for ferromagnetic tunnel junctions with CoFeO_x inserted in the pinned layer was investigated. A junction with a CoFe/CoFeO_x/CoFe as the pinned layer exhibited TMR ratios of 47 % and 43 % after annealing at 350°C and at 375°C respectively, The reason for the improvement of the thermal stability is related to oxygen diffusion from CoFeO_x layer, and there is a possibility that CoFeO_x plays a role of Mn (in MnIr exchange layer) diffusion barrier.
Single domain observation for synthetic antiferromagnetically coupled bits with low aspect ratios Peer-reviewed

N Tezuka, N Koike, K Inomata, S Sugimoto

APPLIED PHYSICS LETTERS　82　(4)　604-606　2003/01

DOI： 10.1063/1.1539549 　

ISSN： 0003-6951
Co₂MnGeホイスラー合金薄膜の構造と磁気特性 Peer-reviewed

岡村進, 手束展規, 猪俣浩一郎, 杉本諭, 村上義弘, 斉藤今朝美, 三谷誠司, 高梨弘毅

J. Magn. Soc. Jpn.　26　(4)　437-440　2002/12/31

DOI： 10.3379/jmsjmag.26.437 　
Magnetic switching properties of GMR spin-valves using SyAF free layers Peer-reviewed

T Nozaki, S Abe, N Tezuka, K Inomata, S Sugimoto

JOURNAL OF THE JAPAN INSTITUTE OF METALS　66　(11)　1078-1082　2002/11

ISSN： 0021-4876

eISSN： 1880-6880
Natural resonance phenomenon and GHz range microwave absorption of (Nd_1-xSm_x)₂Fe₁₄B resin composites

TORU MAEDA, SATOSHI SUGIMOTO, NOBUKI TEZUKA, TOSHIO KAGOTANI, KOICHIRO INOMATA

PROCEEDINGS OF THE SEVENTEETH INTERNATIONAL WORKSHOP ON Rare Earth Magnets and Their Applications, Edited by G.C. Hadjipanisis and M.J.Bonder, Rinton Press, USA　592-599　2002/08
Magnetic switching field and giant magnetoresistance effect of multilayers with synthetic antiferromagnet free layers Peer-reviewed

K Inomata, T Nozaki, N Tezuka, S Sugimoto

APPLIED PHYSICS LETTERS　81　(2)　310-312　2002/07

DOI： 10.1063/1.1490149 　

ISSN： 0003-6951
A thermodynamic study of the HDDR conditions in the Sm2Fe17Nx compound Peer-reviewed

S Ohga, S Sugimoto, N Tezuka, T Kagotani, K Inomata

MATERIALS TRANSACTIONS　43　(3)　459-461　2002/03

DOI： 10.2320/matertrans.43.459 　

ISSN： 1345-9678

eISSN： 1347-5320
Magnetic properties and microwave absorption properties of polymer-protected cobalt nanoparticles Peer-reviewed

Y Kato, S Sugimoto, K Shinohara, N Tezuka, T Kagotani, K Inomata

MATERIALS TRANSACTIONS　43　(3)　406-409　2002/03

DOI： 10.2320/matertrans.43.406 　

ISSN： 1345-9678

eISSN： 1347-5320
Magnetic properties of the Cr(001) surface studied by spin-polarized scanning tunneling spectroscopy Peer-reviewed

M Kleiber, M Bode, R Ravlic, N Tezuka, R Wiesendanger

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS　240　(1-3)　64-69　2002/02

ISSN： 0304-8853
Improvement of coercivity of anisotropic Nd-Fe-BHDDR powders by Ga addition Peer-reviewed

S Sugimoto, H Murai, N Koike, H Nakamura, D Book, N Tezuka, T Kagotani, M Okada, M Homma, K Inomata

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS　239　(1-3)　444-446　2002/02

DOI： 10.1016/S0304-8853(01)00620-5 　

ISSN： 0304-8853
Switching field behavior in antiparallely coupled sub-micrometer scale magnetic elements Peer-reviewed

N Tezuka, E Kitagawa, K Inomata, S Sugimoto, N Kikuchi, Y Shimada

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS　240　(1-3)　294-296　2002/02

DOI： 10.1016/S0304-8853(01)00782-X 　

ISSN： 0304-8853
Spin Switching in Antiferromagnetically Coupled Submicron Magnetic Elements.

Kitagawa E., Nozaki T., Tezuka N., Inomata K., Sugimoto S., Watanabe M., Fujimori H., Masumoto T.

Journal of the Magnetics Society of Japan　26　(4)　422-425　2002
Publisher: The Magnetics Society of Japan
DOI： 10.3379/jmsjmag.26.422 　

ISSN： 0285-0192

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Magnetization reversal of patterned magnetic structures consisting of single and antiferromagnetically (AF) coupled magnetic elements was simulated by Landau-Lifshitz-Gilbert equations. It is considered that AF coupled magnetic elements can make the demagnetization field small. Simulation was carried out for changing saturation magnetization, uniaxial anisotropy, magnetic exchange stiffness constant, interlayer exchange coupling, magnetic layer thickness, nonmagnetic layer thickness and element size. As a result, we found that the switching field of AF coupled magnetic elements became smaller than that of single magnetic elements in submicron elements.
Magnetization reversal of deep submicron magnetic elements Peer-reviewed

N. Tezuka, E. Kitagawa, K. Inomata, S. Sugimoto

INTERMAG Europe 2002 - IEEE International Magnetics Conference　2002
Publisher: Institute of Electrical and Electronics Engineers Inc.
DOI： 10.1109/INTMAG.2002.1001209 　
Application of Permanent Magnet Materials for Microwave Absorbers in the GHz Range

Satoshi Sugimoto, Toru Maeda, Toshio Kagotani, Nobuki Tezuka, Koichiro Inomata

The Papers of Technical Meeting on Magnetics, IEE Japan　MAG-02-164　51-56　2002
Magnetic switching properties of GMR spin-valves using SyAF free layers Peer-reviewed

Takayuki Nozaki, Shinya Abe, Nobuki Tezuka, Koichiro Inomata, Satoshi Sugimoto

Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals　66　(11)　1078-1082　2002
Publisher: Japan Institute of Metals (JIM)
DOI： 10.2320/jinstmet1952.66.11_1078 　

ISSN： 0021-4876
Effect of Co Addition on the GHz Range Microwave Absorption Properties of the Disproportionated Mixture formed from the Sm₂Fe₁₇ Compound Peer-reviewed

Toru Maeda, Satoshi Sugimoto, Nobuki Tezuka, Toshio Kagotani, Koichiro Inomata

Proceeding of The Foourth Pacific Rim International Conference on Advanced Materials and Processing (PRICM4), Ed. by S. Hanada, Z. Zhong, S. W. Nam and R. N. Wright, The Japan Institute of Metals, 2001　2817-2820　2001/12
Effect of Substitution Composition on the Electromagnetic Absorption Properties in Aligned M-type Barium Ferrite Ba_1-xLa_xZn_xFe_12-x-y(Me_0.5Mn_0.5)_yO₁₉ (x=0.0-0.5, Me:,Sn Peer-reviewed

Toshio Kagotani, Daisuke Fujiwara, Hiroyuki Takabayashi, Nobuki Tezuka, Satoshi Sugimoto, Koichiro Inomata, Motofumi Homma

Proceedings of The Fourth Pacific Rim International Conference on Advanced Materials and Processing (PRICM4), Ed. by S. Hanada, Z. Zhong, S. W. Nam and R. N. Wright, The Japan Institute of Metals　2821-2824　2001/12
Thickness and Oxidation Time Dependence of Tunnel Magnetoresistance in Ni-Fe/Co/Al-O/Co Junctions Peer-reviewed

H. Kubota, S. Otsuka, M. Kamijo, N. Tezuka, Y. Ando, C.C. Yu, T. Miyazaki

Journal of the Magnetics Society of Japan　24　(4)　595-598　2000
Publisher: The Magnetics Society of Japan
DOI： 10.3379/jmsjmag.24.595 　

ISSN： 0285-0192

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Ni-Fe/Co/Al-O/Co tunnel junctions with small active areas down to 3 x 3 μm² were fabricated by the micro-fabrication technique. The Al-O insulating layer was prepared by plasma oxidation of a thin sputtered Al film. The dependences of the tunnel magnetoresistance on the thickness of the Al film and the oxidation time were investigated. The interface structure of the junction was observed by using high-resolution electron microscopy. The relationship between the magnetoresistive properties and the interface structure is discussed.
Characterization of the Barrier Layer in Al1-xCox/{ Al1-xCox -Oxide}/Al Tunnel Junctions Peer-reviewed

X.F. Han, J. Murai, M. Hayashi, N. Tezuka, Y. Ando, T. Miyazaki

Journal of the Magnetics Society of Japan　24　(4)　603-606　2000
Publisher: The Magnetics Society of Japan
DOI： 10.3379/jmsjmag.24.603 　

ISSN： 0285-0192

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Oxides of Al_1-xCo_x (x = 0, 0.25, 0.50, 0.75, and 1.0) alloys were chosen as barrier materials in this work. The tunnel junctions consisted of a bottom electrode Al_1-xCo_x and a top electrode Al with an insulating layer {Al_1-xCo_x-oxide} formed by natural oxidation in a baking-box at 333 K. The oxidation time for forming an Al_1-xCo_x-oxide layer on the surface of the bottom Al_1-xCo_x layers was optimized. When tunnel resistances were between 10⁵ and 10⁷ Ωμm² measured at 1 mV and at 4.2 K, the effective barrier height and width of the insulating layers of Al_1-xCo_x-oxide (x = 0.25, 0.5, and 0.75) varied between 0.7 and 2.2 eV and between 1.4 and 1.7 nm, respectively. It is shown that the thin oxide layer of Al_1-xCo_x alloys can be used as a barrier.
Ni80Fe20/Co/N(N=Ta,Cu,Al)/Al-oxide/Co接合における磁気抵抗効果 Peer-reviewed

大坊忠臣, 手束展規, 久保田均, 安藤康夫, 林将光, 宮崎照宣, Changkyung Kim, Ohsung Song

日本応用磁気学会誌　24　(4)　599-602　2000
Publisher: The Magnetics Society of Japan
DOI： 10.3379/jmsjmag.24.599 　

ISSN： 0285-0192

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The effect on the tunneling magnetoresistance (TMR) of inserting the nonmagnetic metals (NMs) Al, Cu, and Ta between the insulator and ferromagnetic layer of a tunnel junctions was investigated. The TMR ratio for a junction with Ta decreased rapidly with increasing Ta thickness, while that for a junction with Al remained more than 50 Å of the thickness. From cross-sectional TEM and AFM measurement, it was found that a junction with thick Al has an insulating layer on both sides of the metallic Al; that is, it would be a double-barrier tunnel junction. We compared the experimental result for the metallic Al thickness dependence of the TMR ratio with the theory of double tunnel junctions. Consequently, the spin diffusion length of Al was estimated to be sub-micrometer.
Applied voltage and temperature dependence of tunneling magnetoresistance Peer-reviewed

N Tezuka, M Oogane, T Miyazaki

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS　198-99　149-151　1999/06

DOI： 10.1016/S0304-8853(98)01056-7 　

ISSN： 0304-8853
Influence of interlayer roughness on magnetoresistive effect of ferromagnetic tunneling junctions Peer-reviewed

Y Ando, M Yokota, N Tezuka, T Miyazaki

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS　198-99　155-157　1999/06

DOI： 10.1016/S0304-8853(98)01053-1 　

ISSN： 0304-8853
Analysis of the interface in ferromagnet/insulator junctions by inelastic-electron-tunneling-spectroscopy Peer-reviewed

Y. Ando, J. Murai, N. Tezuka, T. Miyazaki

J. Magn. Magn. Mater.　198-199　161-163　1999

DOI： 10.1016/S0304-8853(98)01050-6 　
Arイオンミリングによる強磁性トンネル接合の微細加工 Peer-reviewed

大塚茂樹, 上條誠, 手束展規, 久保田均, 宮崎照宣

日本応用磁気学会誌　23　(4)　1305-1308　1999
Publisher: The Magnetics Society of Japan
DOI： 10.3379/jmsjmag.23.1305 　

ISSN： 0285-0192

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The effect of the Ar ion milling process on tunnel magneto-resistance was investigated by using Ar ion milling to make a small hole at the center of the active area of a junction prepared by means of metal masks. Metallic short-circuiting through the material redeposited during Ar ion milling was evaluated by comparing the tunnel resistance before and after the process. The amount of redeposited material was small in the samples produced by the milling process with a higher incident angle of Ar ions. Small Ni-Fe/Co/Al-O/Co junctions with various active area ranged from 9 to 10⁴ μm² were also fabricated. The tunnel resistance increased in inverse proportion to the active area. Many junctions showed a TMR ratio of 9%-13%, which was as large as the value for junctions prepared by means of metal masks.
強磁性体/Al－Oxide/Co接合のトンネル磁気抵抗効果の印加電圧及び温度依存性 Peer-reviewed

大兼幹彦, 手束展規, 宮崎照宣

日本応用磁気学会誌　23　(4)　1297-1300　1999
Publisher: The Magnetics Society of Japan
DOI： 10.3379/jmsjmag.23.1297 　

ISSN： 0285-0192

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Ferromagnetic tunneling junctions with various thicknesses of the first ferromagnetic layer were fabricated. Co and Ni₈₀Fe₂₀ were used as the first ferromagnetic layer, and their thicknesses were varied between 10 and 200 Å. The voltage and temperature dependence of the tunneling magnetoresistance (TMR) ratio and conductance characteristic were investigated for these junctions. A drastic decrease in the conductance near the zero bias in the conductance-voltage characteristics (zero-bias anomaly) was observed in some junctions. A rapid decrease in the TMR ratio below 5 mV and 50 K was also observed in the same junctions. A slight decrease in the TMR ratio above 10 mV and 100 K was observed in all junctions. We investigated the origin of the voltage and temperature dependence of the TMR ratio by taking account of the magnetic impurity and magnon effect.
Ni80Fe20/Al－Oxide/Co接合におけるトンネル磁気抵抗比のNi80Fe20膜厚依存性 Peer-reviewed

大兼幹彦, 手束展規, 宮崎照宣

日本応用磁気学会誌　23　(4)　1309-1312　1999
Publisher: The Magnetics Society of Japan
DOI： 10.3379/jmsjmag.23.1309 　

ISSN： 0285-0192

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Ferromagnetic tunneling junctions with various thicknesses of the first ferromagnetic layer were fabricated. Ni₈₀Fe₂₀ and Co were used as the first ferro-magnetic layer, and their thicknesses were varied between 10 and 200 Å. The tunneling magnetoresistance (TMR) ratio decreased and the shape of the TMR curve changed with decreasing Ni₈₀Fe₂₀ thickness, but changed only slightly with decreasing Co thickness. We calculated the TMR and magnetization curves by using a simple model that takes account of magnetic anisotropy to explain the change in the TMR ratio and the shape of the TMR curve with changing Ni₈₀Fe₂₀ thickness.
Ni80Fe20/Al-oxide/Co接合における磁気抵抗効果のAl-oxide厚依存性 Peer-reviewed

手束展規, 宮崎照宣

日本応用磁気学会誌　23　(4)　1317-1320　1999
Publisher: The Magnetics Society of Japan
DOI： 10.3379/jmsjmag.23.1317 　

ISSN： 0285-0192

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Ferromagnetic tunneling junctions of Ni₈₀Fe₂₀/Al oxide/Co with various Ni₈₀Fe₂₀ and Al-oxide thicknesses were fabricated by magnetron sputtering using metal masks. The thicknesses of Ni₈₀Fe₂₀ were 70, 100, 200, 500, and 1000 Å. The thicknesses of the Al layer ranged from 7 to 80 Å, and the Al oxide films were formed by natural oxidization. The thicker the Ni₈₀Fe₂₀ layer, the larger the optimum Al thickness for the TMR ratio. On the other hand, when the thickness of Ni₈₀Fe₂₀ was constant, the TMR ratio decreased with increasing Al thickness. To clarify the reason for this, AFM images of the Ni₈₀Fe₂₀ surface were measured. The surface roughness of Ni₈₀Fe₂₀ increased with increasing Ni₈₀Fe₂₀ thickness.
Spin-polarized magnetic tunnelling magnetoresistive effects in various junctions Peer-reviewed

T Miyazaki, N Tezuka, S Kumagai, Y Ando, H Kubota, J Murai, T Watabe, M Yokota

JOURNAL OF PHYSICS D-APPLIED PHYSICS　31　(6)　630-636　1998/03

DOI： 10.1088/0022-3727/31/6/009 　

ISSN： 0022-3727
Temperature and applied voltage dependence of magnetoresistance ratio in Fe Al oxide Fe junctions Peer-reviewed

N Tezuka, T Miyazaki

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS　37　(2B)　L218-L220　1998/02

DOI： 10.1143/JJAP.37.L218 　
Barrier height dependence of MR ratio in Fe/Al-oxide/Fe junctions Peer-reviewed

N Tezuka, T Miyazaki

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS　177　1283-1284　1998/01

DOI： 10.1016/S0304-8853(97)00964-5 　

ISSN： 0304-8853
ウェッジ状のAl－O絶縁層を有する強磁性トンネル接合の磁気抵抗効果 Peer-reviewed

横田匡史, 安藤康夫, 手束展規, 宮崎照宣

日本応用磁気学会誌　22　(4)　569-572　1998
Publisher: The Magnetics Society of Japan
DOI： 10.3379/jmsjmag.22.569 　

ISSN： 0285-0192

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Ferromagnetic tunneling junctions of Ni₈₀Fe₂₀ (Py)/Co/Al oxide/Co with wedge-shaped insulators were fabricated. Al oxide films were formed by natural oxidization with various conditions and were checked by FT-IR spectroscopy. The peak intensity and the position depending on the Al thickness were explained by using the 1-D Einstein model. When the oxidization time was less than 50 h, tunneling magnetoresistance (TMR) was observed at about 13 Å of the Al thickness. When the oxidization time became more than 50 h, the thickness shifted to less than 10 Å. The reason for this was considered that Co oxide was formed on the surface of the bottom electrode and became a tunneling barrier with increasing oxidization time. On the other hand, the TMR decreased rapidly with increasing Al thickness. To determine the reason for this, AFM images of the Py/Co/Al surface with various oxidization times were measured. The surface roughness of the Al increased with increasing oxidization time, corresponding to the TMR results.
非弾性電子トンネル分光法（IETS）を用いた強磁性体/絶縁体界面の解析 Peer-reviewed

村井純一郎, 安藤康夫, 手束展規, 宮崎照宣

日本応用磁気学会誌　22　(4)　573-576　1998
Publisher: The Magnetics Society of Japan
DOI： 10.3379/jmsjmag.22.573 　

ISSN： 0285-0192

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Inelastic electron-tunneling spectroscopy (IETS) has been used to investigate the vibrational spectrum in Al/Al₂O₃/CO/AI tunneling junctions with various Co thicknesses (d _Co). A zero-bias anomaly was observed in the conductance curve of the junction with d_Co of 2Å, and decreased with increasing d_Co. The IET spectra of these junctions showed strong negative peaks at 4 mV, corresponding to the zero-bias anomaly, while phonon spectra were observed for the junction with d_Co ≥ 10Å. The peak position was different from that of Al/Al₂O₃/Al. After annealing of the junction with d_Co of 2Å at 250°C for one hour, the zero-bias anomaly decreased and the phonon spectrum appeared.
NiFe/Co/Al2O3/Co/NiFe/FeMn接合のトンネル磁気抵抗効果 Peer-reviewed

熊谷静似, 手束展規, 宮崎照宣

日本応用磁気学会誌　22　(4)　561-564　1998
Publisher: The Magnetics Society of Japan
DOI： 10.3379/jmsjmag.22.561 　

ISSN： 0285-0192

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Spin-valve-type ferromagnetic tunneling junctions using contact metal masks were fabricated, and the annealing effect and temperature dependence of the tunneling magnetoresistance (TMR) ratio and saturated resistance (R_s) were investigated. As-prepared NiFe/Co/Al₂O₃/Co/NiFe/FeMn junctions showed a spin-valve-like MR curve at room temperature. The effect of field annealing was investigated for two reasons: to increase the TMR ratio and: to create an orthogonal magnetic orientation in each of the two magnetic layers. The temperature dependence of the TMR ratio and R_s is affected by the annealing. For the annealed junction, the TMR ratio decreases slightly with increasing temperature and decreases rapidly around 418 K, because of the disappearance of the exchange bias in the FeMn layer.
Temperature dependence of the spin tunneling magnetoresistive effect on NiFe/Co/Al2O3/Co/NiFe/FeMn junctions Peer-reviewed

S Kumagai, N Tezuka, T Miyazaki

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS　36　(11B)　L1498-L1500　1997/11

DOI： 10.1143/JJAP.36.L1498 　

ISSN： 0021-4922
Spin-polarized tunneling magnetoresistive effect in ferromagnet/insulator/ferromagnet junctions Peer-reviewed

T Miyazaki, N Tezuka, S Kumagai

PHYSICA B　237　256-260　1997/07

DOI： 10.1016/S0921-4526(97)00152-X 　

ISSN： 0921-4526
強磁性トンネル接合における絶縁障壁と磁気抵抗 Peer-reviewed

手束展規, 安藤康夫, 宮崎照宣, H.G. Tompkins, S. Tehrani, H. Goronkin

日本応用磁気学会誌　21　(4)　493-496　1997
Publisher: The Magnetics Society of Japan
DOI： 10.3379/jmsjmag.21.493 　

ISSN： 0285-0192

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The dependence of the tunneling magnetoresistive effect on the barrier height was investigated. The magnitude of the barrier height increased with increasing aluminum oxidation temperature and time from 0.3 to 2.3 eV in Fe/Al oxide/Fe junctions. However, those values are smaller than those reported for an Al₂O₃ barrier. A possible reason for this is that the barrier is not pure Al₂O₃, but AIO_x, or another oxide created by interface mixing between Fe and Al oxide. On the other hand, the magnetoresistance ratio in these junctions varied up to 18% at room temperature and up to 18% at 4.2 K. The dependence of the magnetoresistance ratio at 4.2 K on the barrier height is roughly the same as predicted by Slonczewski's theory. This result shows that the effective spin polarization of ferromagnetic electrodes changes according to the barrier height.
Magnetic tunneling effect in Fe/Al2O3/Ni1-xFex junctions Peer-reviewed

N Tezuka, T Miyazaki

JOURNAL OF APPLIED PHYSICS　79　(8)　6262-6264　1996/04

DOI： 10.1063/1.362028 　

ISSN： 0021-8979
Spin polarized tunneling in ferromagnet insulator ferromagnet junctions Peer-reviewed

T Miyazaki, N Tezuka

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS　151　(3)　403-410　1995/12

DOI： 10.1016/0304-8853(95)00563-3 　

ISSN： 0304-8853
GIANT MAGNETIC TUNNELING EFFECT IN FE/AL2O3/FE JUNCTION Peer-reviewed

T MIYAZAKI, N TEZUKA

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS　139　(3)　L231-L234　1995/01

DOI： 10.1016/0304-8853(95)90001-2 　

ISSN： 0304-8853
強磁性/Al2O3/強磁性接合の磁気トンネリング効果 Peer-reviewed

手束展規, 安藤康夫, 宮崎照宣

日本応用磁気学会誌　19　369-372　1995

DOI： 10.3379/jmsjmag.19.369 　
Fe，Ni，Co金属の結晶粒径と保磁力 Peer-reviewed

佐藤文隆, 手束展規, 桜井伴明, 宮崎照宣

日本応用磁気学会誌　17　886-891　1993

DOI： 10.3379/jmsjmag.17.886

Show all ︎Show first 5

Misc. 54

Influence of Sm-rich Phase on Magnetic Properties of Surface Modified Sm-Fe-N Powder Prepared by Reduction-diffusion Process

松浦昌志, 松田瑠香, 手束展規, 杉本諭, 杉本諭, 石川尚, 米山幸伸

電気学会論文誌 A　142　(7)　2022

ISSN： 0385-4205
Oxidation State and Coercivity of Nd-Fe-B/Nd Thin Films

MATSUURA Masashi, FUKADA Togo, GOTO Ryota, TEZUKA Nobuki, SUGIMOTO Satoshi

2009　(60)　59-63　2009/08/05
Tunnel Magnetoresistance in Magnetic Tunnel Junctions with Co-based Full-Heusler Electrodes

TEZUKA N., IKEDA N., SUGIMOTO S., INOMATA K.

153　1-6　2007/02/27

ISSN： 1340-7562
Detection of magnetization reversal of single Co/Pt dot

KATO T, KIKUCHI N, OKAMOTO S, KITAKAMI O, TEZUKA N, SUGIMOTO S

電気学会研究会資料. MC, 金属・セラミックス研究会　2006　(1)　5-9　2006/11/28
Heusler alloy/semiconductor hybrid structures

A. Hirohata, A. Kikuchi, N. Tezuka, K. Inomata, J. S. Claydon, Y. B. Xu, G. van der Laan

CURRENT OPINION IN SOLID STATE & MATERIALS SCIENCE　10　(2)　93-107　2006/04

DOI： 10.1016/j.cossms.2006.11.006 　

ISSN： 1359-0286

eISSN： 1879-0348
Tunnel magnetoresistance enhancement in ferromagnetic tunnel junctions with ferromagnetic nano-particle layer insertion

H. Sukegawa, S. Nakamura, A. Hirohata, N. Tezuka, N. Tezuka, S. Sugimoto, K. Inomata, K. Inomata

INTERMAG ASIA 2005: Digests of the IEEE International Magnetics Conference　1002　2005/12/12
Substantial reduction of critical current for magnetization switching in an exchange-biased spin valve (vol 3, pg 361, 2004)

Y Jiang, T Nozaki, S Abe, T Ochiai, A Hirohata, N Tezuka, K Inomata

NATURE MATERIALS　4　(4)　353-353　2005/04

DOI： 10.1038/nmat1355 　

ISSN： 1476-1122
24aXN-8 Magnetic properties of epitaxial Co_2Cr_<1-x>Fe_xAl full Heusler alloy films

Hirohata A, Kurebayashi K., Okamura S., Tezuka N., Inomata K.

Meeting abstracts of the Physical Society of Japan　60　(1)　408-408　2005/03/04
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Structural and Magnetic Properties of L2_1-Structured Co_2(Cr, Fe)Al Thin Films

HIROHATA A., KUREBAYASHI H., OKAMURA S., KIKUCHI M., MASAKI T., NOZAKI T., TEZUKA N., INOMATA K.

28　399-399　2004/09/21
Structural, Magnetic and Electrical Transport Properties of Co_2V_<1-x>Fe_xAl Heusler Alloy Films

MIYAZAKI A., OKAMURA S., TEZUKA N., INOMATA K.

28　401-401　2004/09/21
TMR properties of the microfabricated Co_2(Cr_<1-x>Fe_x)Al/Al-O/Co_<90>Fe_<10> magnetic tunnel junctions

OKAMURA S., MIYAZAKI A., TEZUKA N., SUGIMOTO S., INOMATA K.

28　400-400　2004/09/21
Magnetoresistance of MTJs Using Co_2CrGa Full-Heusler Alloy Films

KIKUCHI M., MASAKI T., TEZUKA N., SUGIMOTO S., INOMATA K.

28　403-403　2004/09/21
Crystal Structure, Magnetic and Conduction Properties of Co_2CrGa Heusler Alloy

MASAKI T., KIKUCHI M., TEZUKA N., SUGIMOTO S., INOMATA K.

28　402-402　2004/09/21
Thermal Stability of Synthetic Ferrimagnetic Elements

SAKURADA K., TEZUKA N., SUGIMOTO S., INOMATA K.

28　138-138　2004/09/21
Structure and Magnetic Properties of Co Ferrite Thin Films

GOTO R., TEZUKA N., SUGIMOTO S., INOMATA K.

28　303-303　2004/09/21
Quantum Oscillation Effect in Magnetic Tunnel Junctions with a Ru Spacer Layer

NOZAKI T., TEZUKA N., SUGIMOTO S., INOMATA K.

28　107-107　2004/09/21
Tunnel Magnetoresistance Enhancement in a Double Tunnel Junction with Single Discontinuous Ferromagnetic Layer Insertion

SUKEGAWA H., NAKAMURA S., TEZUKA N., SUGIMOTO S., INOMATA K.

28　112-112　2004/09/21
Crystalline Growth and Magnetic/Electrical Transport Properties of Fe/MgO Layers Grown on GaAs(100)

KUREBAYASHI H., HIROHATA A., TEZUKA N., SUGIMOTO S., INOMATA K.

28　104-104　2004/09/21
Current Induced Magnetization Switching in the CPP-GMR Device with a Synthetic Antiferromagnetic free Layer

OCHIAI T., JIANG Yong, HIROHATA A., TEZUKA N., SUGIMOTO S., INOMATA K.

28　101-101　2004/09/21
13aWB-4 Structural and Magnetic Properties of Co_2Cr_<1-x>Fe_xAl Full-Heusler Thin Films Grown on GaAs(001)

Hirohata A, Kurebayashi K, Okamura S, Tezuka N, Inomata K

Meeting abstracts of the Physical Society of Japan　59　(2)　383-383　2004/08/25
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
28aXR-6 Structural and Magnetic Properties of Co_2(Cr,Fe)Al Full-Heusler Alloys Grown on GaAs(100) Substrates

Hirohata A., Kurebayashi H., Okamura S., Tezuka N., Inomata K.

Meeting abstracts of the Physical Society of Japan　59　(1)　485-485　2004/03/03
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Tunneling magnetoresistance in magnetic tunnel junctions using a full-Heusler alloy electrode

INOMATA Koichiro, OKAMURA Susumu, GOTO Ryota, TEZUKA Nobuki

134　7-12　2004/01/29

ISSN： 1340-7562
Magnetoresistance of the magnetic tunnel junctions with Zn_<0.4>Fe_<2.6>O_4 thin films

NISHIMURA Kazumasa, TEZUKA Nobuki, SUGIMOTO Satoshi, INOMATA Koichiro

2004　(1)　1-6　2004/01/15
CPP-GMR enhancement in spin valve films using ultrathin Ru layer

ABE S., JIANG Yong, TEZUKA N., INOMATA K.

2004　(1)　7-12　2004/01/15
高密度磁気メモリ

安藤康夫, 手束展規, 大野裕三, 栗野浩之, 久保田均, 大野英男

電子材料　43　(1)　136-141　2004
フルホイスラー合金を用いたスピントンネル接合 (特集スピントロニクス(1)スピン伝導)

猪俣浩一郎, 手束展規, 岡村進

マテリアルインテグレ-ション　16　(9)　1-4　2003/09
Publisher: ティ-・アイ・シ-
ISSN： 1344-7858
Magnetoresistance Effect of MTJs using a Co_2(Cr_<1-x>Fe_x)Al Full-Heusler Alloy Film

OKAMURA Susumu, GOTO Ryota, TEZUKA Nobuki, INOMATA Koichiro

27　267-267　2003/09/01

ISSN： 1340-8100
Spin switching properties of magnetic tunnel junctions with a synthetic antiferromagnet free layer

NOZAKI T., TEZUKA N., SUGIMOTO S., INOMATA K.

27　276-276　2003/09/01

ISSN： 1340-8100
Effect of Microstructure on the Resonance Frequency in the Y_2Fe_<14>B/Fe_3B Nanocomposite Alloys

MAEDA Toru, SUGIMOTO Satoshi, KAGOTANI Toshio, TEZUKA Nobuki, INOMATA Koichiro

27　407-407　2003/09/01

ISSN： 1340-8100
CPP-GMR in spin valve films with ultrathin Ru layer

ABE S., YONG J., TEZUKA N., INOMATA K.

27　30-30　2003/09/01

ISSN： 1340-8100
Microwave absorption of Rare earth-Iron-Boron compounds in the GHz range

Maeda Toru, Sugimoto Satoshi, Kagotani Toshio, Tezuka Nobuki, Inomata Koichiro

Proceedings of the IEICE General Conference　2003　(1)　385-385　2003/03/03
Publisher: The Institute of Electronics, Information and Communication Engineers
Current technology and future prospect of MRAM

INOMATA Koichiro, TEZUKA Nobuki

71　(11)　1347-1351　2002/11/10
Publisher: 応用物理学会
ISSN： 0369-8009
Heat Treatment Properties of Ferromagnetic Tunnel Junction Using CoFe/CoFeO_x/CoFe Pinned Layer

OCHIAI T., TEZUKA N., INOMATA K., SUGIMOTO S.

26　13-13　2002/09/01

ISSN： 1340-8100
Magnetization State and Spin Switching Field in Antiferromagnetically Coupled Submicron Elements

KOIKE N., TEZUKA N., INOMATA K., SUGIMOTO S.

26　15-15　2002/09/01

ISSN： 1340-8100
Structure of Zn_xFe_<3-x>O_4 thin films and their magnetic and electrical properties

NISHIMURA K., TEZUKA N., INOMATA K., SUGIMOTO S.

26　452-452　2002/09/01

ISSN： 1340-8100
Magnetization configuration of antiferromagnetically coupled submicron elements

Tezuka N., Koike N., Inomata N., Sugimoto S.

Meeting abstracts of the Physical Society of Japan　57　(2)　337-337　2002/08/13
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Magnetization Properties in submicron antiparallely coupled films

Tezuka N., Kitagawa E., Inomata K., Sugimoto S.

Meeting abstracts of the Physical Society of Japan　56　(2)　336-336　2001/09/03
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Structural and magnetic properties of Co_2MnGe Heusler alloy films

OKAMURA S., TEZUKA N., INOMATA K., SUGIMOTO S., MURAKAMI Y., SAITO K., MITANI S., TAKANASHI K.

25　64-64　2001/09/01

ISSN： 1340-8100
Spin switching in antiferromagnetically coupled submicron magnetic elements

KITAGAWA E., NOZAKI T., TEZUKA N., INOMATA K., SUGIMOTO S., WATANABE M., FUJIMORI H., MASUMOTO K.

25　325-325　2001/09/01

ISSN： 1340-8100
GHz-Range Electromagnetic Wave Absorption of Sub-micron Iron Particles produced by a Disproportionation Reaction

Maeda Toru, Tezuka Nobuki, Kagotani Toshio, Book David, Sugimoto Satoshi, Inomata Koichiro, Ota Hiroyasu, Houjou Yuji

Proceedings of the IEICE General Conference　2001　(1)　372-372　2001/03/07
Publisher: The Institute of Electronics, Information and Communication Engineers
Characterization of the barrier layer in Al_<1-x>Co_x/{Al_<1-x>Co_x-oxide}/Al tunnel junctions

HAN X. F., MURAI J., TEZUKA N., KUBOTA H., ANDO Y., MIYAZAKI T.

23　278-278　1999/10/01
Tunnel magnetoresistance effect for Ni_<80>Fe_<20>Co/N(N=Ta, Al)/Al-oxide/Co junctions

DAIBOU T., TEZUKA N., KUBOTA H., ANDO Y., MIYAZAKI T.

23　273-273　1999/10/01
The dependence of TMR on plasma oxidation time and Al thickness in Ni-Fe/Co/Al-O/Co junctions

KUBOTA H., OTSUKA S., KAMIJO M., YU C. C., TEZUKA N., ANDO Y., MIYAZAKI T.

23　272-272　1999/10/01
26pPSA-46 Tunnel magnetoreisistance effect for Ni_<80>Fe_<20>/Co/N/N-oxide/Co(N=Ta, Al)junctions

Daibou T, Tezuka N, Kubota H, Ando Y, Miyazaki T

Meeting abstracts of the Physical Society of Japan　54　(2)　420-420　1999/09/03
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Magnetoresistive Effect for NiFe/Co/ Al₂O₃ /Co/NiFe/ FeMn Junctions

S. Kumagai, N. Tezuka, T. Miyazaki

J. Magn. Soc. Jpn.　22　5561　1998
Analysis of the interlayer in ferromagnet/insulator junction by inelastic-electron-tunneling-spectroscopy.

MURAI J., ANDO Y., TEZUKA N., MIYAZAKI T.

21　174-174　1997/10/01
Magnetoresistance effect in ferromagnetic tunneling junctions with wedge shaped insulator

YOKOTA M., ANDO Y., TEZUKA N., MIYAZAKI T.

21　173-173　1997/10/01
Ferromagnetic tunneling effect in NiFe/Co/Al_2O_3/Co/NiFe/FeMn junctions.

KUMAGAI S., TEZUKA N., MIYAZAKI T.

21　170-170　1997/10/01
7a-YG-7 Magnetoresistive effect in ferromagnetic tunneling junctions.

Kumagai S., Tezuka N., Miyazaki T.

Meeting abstracts of the Physical Society of Japan　52　(2)　521-521　1997/09/16
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
29P-WB-1 Magnetoresistance effect in ferromagnetic tunneling junctions

Miyazaki T., Tezuka N., Kumagai S.

Meeting abstracts of the Physical Society of Japan　52　(1)　481-481　1997/03/17
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Relationship between the barrier and magnetoresistance effect in ferromagnetic tunneling junctions

TEZUKA N., ANDO Y., MIYAZAKI T., TOMPKINS H. G., TEHRANI S. T., GORONKIN H. G.

20　136-136　1996/09/01
3a-YD-11 The relationship between the barrier and the MR ratio in the ferromagnetic tunneling junctions

Tezuka N., Miyazaki T.

Abstracts of the meeting of the Physical Society of Japan. Annual meeting　51　(3)　215-215　1996/03/15
Publisher: The Physical Society of Japan (JPS)
EXPERIMENTAL STUDY OF MAGNETIC TUNNELING VALVE EFFECT

T.Miyazaki, N.Tezuka

Proceedings of the Third International Symposium on Physics of Magnetic Materials　850-856　1995
3p-YA-7 Magnetic tunneling effect in ferromagnet/Al-Al_2O_3/ferromagnet junction

Tezuka N, Ando Y, Miyazaki T

Abstracts of the meeting of the Physical Society of Japan. Sectional meeting　1994　(3)　84-84　1994/08/16
Publisher: The Physical Society of Japan (JPS)

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Research Projects 3

高性能永久磁石に関する研究 Competitive

2000/09 - Present
高周波磁性材料の開発 Competitive

2000/09 - Present
スピントランスポートデバイスに関する研究 Competitive

System: The Other Research Programs

1994/04 - Present

Social Activities 3

イノベーションジャパン

2004/09/28 - 2004/09/30

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最新の研究成果を一般に広く伝え，専門外の人たちにも研究成果を共通の知識としてもらうことに協力
リフレッシュ理科教室

2001/08/06 - 2001/08/07

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小・中学生，ならびに，先生に理科の面白さを知ってもらい，現場の先生方に基礎から最新の科学技術までを知る機会を提供
東北大学サイエンスカフェ

2007/07/30 -

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一般市民と研究者が，コーヒーカップを片手にサイエンスについて気軽に話し合い，サイエンスの楽しさと社会貢献の姿を知ってもらう場に協力．

Other 3

高スピン分極材料を用いた高出力磁気利用センサの開発

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高スピン分極材料を開発し，磁気利用センサの高性能化を試みる
反平行結合膜を用いたナノサイズCPP-GMR素子の高再生出力に関する研究

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反平行結合膜をフリー層に用いた，CPP-GMR素子の再生出力増大に関する研究．
低磁界・低電力駆動サブミクロン磁性素子の開発

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サブミクロン磁性素子の低磁界磁化反転に関する研究