Development of magnetic tunnel junctions with huge tunnel magnetoresistance through improving half-metallic feature at junction interfaces
Project/Area Number |
16H03852
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Research Category |
Grant-in-Aid for Scientific Research (B)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Applied materials
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Research Institution | National Institute for Materials Science |
Principal Investigator |
Sukegawa Hiroaki 国立研究開発法人物質・材料研究機構, 磁性・スピントロニクス材料研究拠点, 主幹研究員 (30462518)
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Co-Investigator(Kenkyū-buntansha) |
三浦 良雄 国立研究開発法人物質・材料研究機構, 磁性・スピントロニクス材料研究拠点, 独立研究者 (10361198)
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Research Collaborator |
MITANI Seiji
MASUDA Keisuke
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Project Period (FY) |
2016-04-01 – 2019-03-31
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Project Status |
Completed (Fiscal Year 2018)
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Budget Amount *help |
¥16,900,000 (Direct Cost: ¥13,000,000、Indirect Cost: ¥3,900,000)
Fiscal Year 2018: ¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000)
Fiscal Year 2017: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2016: ¥8,840,000 (Direct Cost: ¥6,800,000、Indirect Cost: ¥2,040,000)
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Keywords | スピントロニクス / ハーフメタル / 薄膜成長 / 強磁性トンネル接合 / 第一原理計算 / スピンエレクトロニクス / 超薄膜 / 磁性 / 磁性薄膜 |
Outline of Final Research Achievements |
We developed elemental technologies toward huge tunnel magnetoresistance (TMR) by focusing on interface states at half-metallic Heusler alloys and an MgAl2O4 barrier. (1) We found a promising interface layer material, FeAl alloys, through solid-state Al atomic diffusion effect observed at an ultrathin Al-containing alloy layer and a barrier. (2) By using MgAl2O4 barriers, perfectly lattice-matched interfaces with Heusler alloys were achieved. Additionally, a very high quality Heusler alloy layer was successfully grown on the MgAl2O4 barrier. (3) Advanced first-principles-based transport calculation methods have been developed. Especially, the calculations revealed excellent bias voltage dependence of TMR in an MgAl2O4 barrier MTJ, and a large exchange stiffness constant in Co-terminated CoFe, which is one of the most important factors for observing large TMR ratio at room temperature.
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Academic Significance and Societal Importance of the Research Achievements |
本課題期間内では当初狙っていたTMR比の更新までは到達しなかったが、実現に向けた幅広い重要なMTJの要素技術確立が達成されたと考えられる。特に原子レベル固相拡散現象が高度な界面構造の作製に有効利用できることが見いだされ、これは新しいMTJ設計指針を与えるものである。また、MgAl2O4をバリアとして用いることの優位性が明確になった。当初予定していなかった多結晶素子化の技術も確立され、実用素子への急速な展開へも期待されることから磁気メモリー、磁気センサーへの活用にもつながると期待される。理論計算技術の向上もめざましく、幅広い観点からMTJの解析が可能になったことの学術的意義は大きい。
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Report
(4 results)
Research Products
(54 results)
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[Presentation] Magnetotransport properties in the magnetic junctions with a Cu(In0.8Ga0.2)Se2 semiconductor spacer and Co2Fe(Ga0.5Ge0.5) ferromagnetic electrodes2016
Author(s)
K. Mukaiyama, K. Masuda, S. Kasai, Y. Takahashi, P. Cheng, I. Ikhtiar, Y. Miura, T. Ohkubo, S. Mitani, K. Hono
Organizer
61st Annual Conference on Magnetism and Magnetic Materials (MMM2016)
Place of Presentation
New Orleans, Louisiana, USA
Year and Date
2016-10-31
Related Report
Int'l Joint Research
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