2007 Fiscal Year Final Research Report Summary
Interfacial Half-Metallicity and Spin Injection in Oxide Hetrostructures
| Project/Area Number |
17360020
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Thin film/Surface and interfacial physical properties
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| Research Institution | Nagoya University |
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Principal Investigator |
ASANO Hidefumi Nagoya University, Graduate School of Eng, Professor (50262853)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUI Masaaki Toyota Rilcen, Fellow (90013531)
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| Project Period (FY) |
2005 – 2007
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| Keywords | Spin Tunneling / Half-Metal / Spin injection / Magnetoresistance Effect / Andreev Reflection |
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| Research Abstract |
1. Andreev reflection study by using superconducting junctions combined with XPS analysis has indicated that the intrrfavial spin polarization of La_0.7Sr_0.3MnO_3 (LSMO) films is strongly influenced by detailed interfacial structures such as the existence oldie SrO layer It is demonstrated that the junction method using NbN as a superconducting electrode is a versatile technique for measuring spin polarization of various ferromagnetic matmrialsincluding half-metals
2. By means of LSMO polycrystalline films we have examined and analyzed the underlying mechanism and dominant factors of low field. intergrain magnetoresstance (MB) which originate from the half-metallic grain boundaries of LSMO. The results of LSMO polycrystalline films on Si//Y52/Ba_0.4Sr_0.6Ti_O3 with controlled grain sizes have shown that the intergrain MR is strongly dependent on grain-boundary resistances of polycrystalline films. We have developed the new model that by considering spin dependent scattering as well as
… More
spin dependent tunneling can quantitatively explain the relationship among the intergarin-MR ratio, spin polarization, and grain-boundary resistances.
3. High-quality Sr_2OrReOs (SCRO) films with the long-range order parameter of 0.98 can be grown onto the lattice-matched substrate of SrTiO_3. The syncrotron radiation photoelectron spectroscopy of the interfaces between the SCRO films and various insulating materials has shown that the half-metallic electronic stricture, as evidenced by the multiple-structure of the Re spectra and the valence band spectra, is achieved for the SCRO/MgO interface. High spin polarization of SCRO is also suggested by the properties (TMR ratio of 114% at 42K) of SCRO/MgO/Co junctions.
4. Highly oriented CoMnGe Henslar alloy films and their multilayer devices with MgO barrier can be grown onto Si substrates by the use of Ni'Pa seed and Cr bur layers. Moreover the control of (100) and (111) orientations can be achieved far Hensler alloy films. The study that enables the growth of highly oriented half-metallic Heusler alloy films onto a practically useful substrate of Si, instead of a single crystal MgO subtsrtate, is technologically important in view of their spintronic applications. Less
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[Presentation] Magnetic properties and electronic structures of Fe_2Cr_1-xMxSi (M=Ti, V) Heusler alloy2008
Author(s)
K. Yamaji, Y. Nakamura, Y. Takeda, S. Yoshimura, H. Asano, M. Matsui, S. Ishida, A. Kimura, E. Ikenaga, R. Rajanikanth
Organizer
The 55th Spring Meeting, The Japan Society of Applied Physics and Related Societies
Place of Presentation
Nihon Univ., Funabashi
Year and Date
20080327-30
Description
「研究成果報告書概要(欧文)」より
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[Presentation] Structures and magnetism of Fe_2Cr_i-x. MxSi (M=Ti, V) full-Heusler alloy2008
Author(s)
N. Fukatani, Y. Nakamura, K. Yamaji, Y. Takeda, S. Yoshimura H. Asano, M. Matsui, S. Ishida, R. Rajanikanth, K. Hono
Organizer
The 142nd Spring Meeting, 2008, Japan Institute of Metals, Mar.
Place of Presentation
Masashi institute of Technology, Tokyo
Year and Date
20080026-28
Description
「研究成果報告書概要(欧文)」より
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[Presentation] ハーフメタルにおける機能探索2008
Author(s)
浅野秀文, 竹田陽一, 山地一史, 岡武宏, 中村泰貴, 加藤史也, 吉村哲, 松井正顯
Organizer
第9回 金属スピントロニクスセミナー
Place of Presentation
東北大学
Year and Date
2008-02-25
Description
「研究成果報告書概要(和文)」より
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[Presentation] Exploration of new functionalities in half-metals2008
Author(s)
H. Asano, Y. Takeda, K. Yamaji, T. Oka, Y. Nakamura, F. Katoh, J. Thong, S. Yoshimura, M. Matsui
Organizer
The 9th Spintronics Seminar, 2008
Place of Presentation
Tohoku Univ, Sendai
Year and Date
2008-02-25
Description
「研究成果報告書概要(欧文)」より
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[Presentation] Crystal structures and magnetic properties of bulks and thin films of Fe_2Cr_1xTi xSi Heusler alloy2007
Author(s)
Y. Nakamura, K. Yamaji, Y. Takeda, S. Yoshimura, H. Asano, M. Matsui, A. Kimura, S. Ishida
Organizer
The 141st Autumn Meeting, 2007, Japan Institute of Metals
Place of Presentation
Gifu Univ., Gifu
Year and Date
20070919-21
Description
「研究成果報告書概要(欧文)」より
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[Presentation] Fabrication of GMR multiplayer films using Co-based Heusler alloys2007
Author(s)
C. Shishikura, Y. Watanabe, Y. Takeda, S. Yoshimura, H. Asano, M. Matsui
Organizer
The 141st AutumnMeeting, 2007, Japan Institute of Metals, Sept. 2007, Gakushuin Univ, Tokyo
Place of Presentation
Gifu Univ., Gifu
Year and Date
20070019-21
Description
「研究成果報告書概要(欧文)」より
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[Presentation] Ni_2MnGaの中間相変態と磁性2006
Author(s)
中倉俊典, 浜口友彰, 吉村哲, 浅野秀文, 松井正顯
Organizer
日本金属学会 2006年春季(第138回)大会
Place of Presentation
早稲田大学、東京
Year and Date
20060321-23
Description
「研究成果報告書概要(和文)」より
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[Presentation] Ni_2MnGaのマルテンサイト変態2005
Author(s)
中倉俊典, 村上大地, 浜口友彰, 大森和彦, 浅野秀文, 松井正顯
Organizer
日本金属学会2005年秋季(第137回)大会
Place of Presentation
広島大学
Year and Date
20050928-30
Description
「研究成果報告書概要(和文)」より
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[Presentation] Martensitic transformation of Ni_2MnGa2005
Author(s)
T. Nakakura, D. Murakami, T. Hamaguchi, K. Ohmori, H. Asano, M. Matsui
Organizer
The 137th Autumn Meeting, 2005, Japan Insititute of Metals
Place of Presentation
Hiroshima
Year and Date
20050928-30
Description
「研究成果報告書概要(欧文)」より
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[Presentation] Ni_2MnGaの中間相変態と磁性2005
Author(s)
中倉俊典, 村上大地, 竹田陽一, 浅野秀文, 松井正顯
Organizer
第29回 日本応用磁気学会学術講演会
Place of Presentation
信州大学工学部
Year and Date
20050919-22
Description
「研究成果報告書概要(和文)」より
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