Study on Room Temperature Ferromagnetic Nitride Semiconductor Nanostructures and Nanospintronics Device Application

2008 Fiscal Year Final Research Report

• Project/Area Number: 18360009
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Applied materials science/Crystal engineering
• Research Institution: Osaka University
• Principal Investigator: ASAHI Hajime Osaka University, 産業科学研究所, 教授 (90192947)
• Co-Investigator(Kenkyū-buntansha): HASEGAWA Shigehiko 大阪大学, 産業科学研究所, 准教授 (50189528) ; EMURA Shuichi 大阪大学, 産業科学研究所, 助教 (90127192) ; ZHOU Ikai 大阪大学, 産業科学研究所, 助教 (60346179)
• Project Period (FY): 2006 – 2008
• Keywords: スピンエレクトロニクス / 半導体物性 / MBE / ナノ材料 / 結晶工学

Research Abstract

(1) GaGdN/GaN超格子構造を成長し、キャリア誘起磁性による磁化の向上を観測した。
(2) 室温強磁性を示すGaCrNナノロッド構造の成長を実現した。
(3) GaGdN を低温成長することにより、Gd 濃度の増加とそれに伴う飽和磁化の大幅な増大を実現した。Si の同時ドーピングにより更なる飽和磁化の増大が可能なことを示した。
(4) Alフラックスを減少させて成長することにより、ヘテロ界面が平坦でAlドロップレットのない良好なGaCrN/AlN多重量子ディスク(MQDisk)ナノロッド構造の成長に成功した。
(5) GaCrN/AlN/GaCrN 三層構造ダイオードを作製し、77K においてトンネル磁気抵抗(TMR)効果を観測した。全半導体ベースのTMR デバイスでは最高の温度でのTMR 効果の観測である。
(6) AlNの代わりにAlGaNに置換えたGaCrN/AlGaN-MQW構造とすることによっても平坦なヘテロ界面を持つ良好なMQW構造が成長可能なことが分かった。この知見に基づき、AlGaNGaCrN/AlGaN三層構造磁気トンネルデバイスを試作した。

Research Products

• [Journal Article] Crystal growth and characterization of GaCrN nanorods on Si substrate (2009)
  • Author(s): H. Tambo, S. Kimura, Y. Yamauchi, Y. Hiromura, S. Emura, S. Hasegawa and H. Asahi
  • Journal Title: Journal of Crystal Growth (in press)
  • Peer Reviewed
• [Journal Article] Structural and magnetic properties of GaGdN/GaN superlattice structures (2009)
  • Author(s): Y. K. Zhou, S.W. Choi, S. Kimura, S. Emura, S. Hasegawa and H. Asahi
  • Journal Title: Thin Solid Films (in press)
  • Peer Reviewed
• [Journal Article] Structural properties of AlCrN, GaCrN and InCrN (2009)
  • Author(s): S. Kimura, S. Emura, K. Tokuda, Y. K. Zhou, S. Hasegawa and H. Asahi
  • Journal Title: J. Crystal Growth 311 Pages: 2046-2048
  • Peer Reviewed
• [Journal Article] Formation of aligned CrN nanoclusters in Cr-deltadoped GaN (2009)
  • Author(s): Y. K. Zhou, S. Kimura, S. Emura, S. Hasegawa and H. Asahi
  • Journal Title: J. Phys. : Condens. Matter 21 Pages: 064216-1-064216-4
  • Peer Reviewed
• [Journal Article] Growth and characterization of InCrN and(In, Ga, Cr)N (2008)
  • Author(s): S. Kimura, S. Emura, K. Tokuda, Y. Hiromura, S. Hayakawa, Y.K. Zhou, S. Hasegawa and H. Asahi
  • Journal Title: Phys. Stat. Sol (c)5 Pages: 1532-1535
  • Peer Reviewed
• [Journal Article] Electronic structure of Ga1-xCrxN and Si-doping effects studied by photoemission and X-ray absorption spectroscopy (2008)
  • Author(s): G. S. Song, M. Kobayashi, J. I. Hwang, T. Kataoka, M. Takizawa, A. Fujimori, T. Ohkouchi, Y. Takeda, T. Okane, Y. Saitoh, H. Yamagami, F.-H. Chang, L. Lee, H.-J. Lin, D. J. Huang, C. T. Chen, S. Kimura, M. Funakoshi, S. Hasegawa, and H. Asahi
  • Journal Title: Phys. Rev. B 78 Pages: 033304-1-033304-4
  • Peer Reviewed
• [Journal Article] Large magnetization in high Gdconcentration GaGdN and Si-doped GaGdN grown at low temperatures (2008)
  • Author(s): Y. K. Zhou, S. W. Choi, S. Emura, S. Hasegawa and H. Asahi
  • Journal Title: Appl. Phys. Lett 92 Pages: 6062505-1-6062505-3
  • Peer Reviewed
• [Journal Article] Low temperature molecular-beam epitaxy growth of cubic GaCrN (2008)
  • Author(s): S. Kimura, S. Emura, Y. Yamauchi, Y. K. Zhou, S. Hasegawa and H. Asahi
  • Journal Title: J. Cryst. Growth 310 Pages: 40-46
  • Peer Reviewed
• [Journal Article] Cr atom alignment in Cr-delta-doped GaN (2007)
  • Author(s): S. Kimura, S. Emura, H. Ofuchi, Y. Nakata, Y. K. Zhou, C. W. Choi, Y. Yamauchi, S. Hasegawa and H. Asahi
  • Journal Title: American Institute of Physics CP 882 Pages: 410-412
  • Peer Reviewed
• [Journal Article] Growth and Characterization of Ferromagnetic Cubic GaCrN: Structural and magnetic properties (2007)
  • Author(s): S. Kimura, S. Emura, H. Ofuchi, Y .K. Zhou, S. Hasegawa and H. Asahi
  • Journal Title: J. Cryst. Growth 301-322 Pages: 651-655
  • Peer Reviewed
• [Journal Article] Molecular-beam epitaxy growth and characterization of ferromagnetic cubic GaCrN on GaAs substrate (2007)
  • Author(s): S. Kobayashi, S. Shanthi, S. Kimura, Y. K. Zhou, S. Emura, S. Hasegawa and H. Asahi
  • Journal Title: J. Cryst. Growth 308 Pages: 58-62
  • Peer Reviewed
• [Journal Article] Tunnel magnetoresistance in GaCrN/AlN/GaCrN ferromagnetic semiconductor tunnel junctions (2006)
  • Author(s): M. S. Kim, Y. K. Zhou, M. Funakoshi, S. Emura, S. Hasegawa and H. Asahi
  • Journal Title: Appl. Phys. Lett 89 Pages: 232511-1-232511-3
  • Peer Reviewed
• [Journal Article] Local crystal structure and local electronic structure around Cr in low-temperature-grown GaCrN layers (2006)
  • Author(s): M. Hashimoto, S. Emura, H. Tanaka, T. Honma, N. Umesaki, S. Hasegawa and H. Asahi
  • Journal Title: J. Appl Phys 100 Pages: 103907-1-103907-6
  • Peer Reviewed
• [Journal Article] Ferromagnetism in short-period GaGdN/GaN superlattices grown by RF-MBE (2006)
  • Author(s): S. W. Choi, Y. K. Zhou, M. S. Kim, S. Kimura, S. Emura, S. Hasegawa and H. Asahi
  • Journal Title: Phys. Stat. Sol (a)203 Pages: 2774-2777
  • Peer Reviewed
• [Journal Article] Nature of deep level defects in GaCrN diluted magnetic semiconductor (2006)
  • Author(s): S. Shanthi, S. Kimura, M.S. Kim, S. Kobayashi, Y.K. Zhou, H. Hasegawa and H. Asahi
  • Journal Title: Jpn. J. Appl. Phys 45(4B) Pages: 3522-3525
  • Peer Reviewed
• [Journal Article] optical and electrical properties of GaN and AlN doped with rare-earth element Gd (2006)
  • Author(s): S. W. Choi, Y. K. Zhou, S. Emura, N. Teraguchi, A. Suzuki and H. Asahi, Magnetic
  • Journal Title: Phys. Stat. Sol (c)3 Pages: 2250-2253
  • Peer Reviewed
• [Journal Article] Ferromagnetic cubic GaCrN epitaxial growth over MgO substarte-effect of growth condition (2006)
  • Author(s): S. Kimura, S. Shanthi, Y.K. Zhou, M.S. Kim, S. Kobayashi, S. Emura, S. Hasegawa and H. Asahi
  • Journal Title: Jpn. J. Appl. Phys 45(1A) Pages: 76-78
  • Peer Reviewed
• [Journal Article] Emission spectra from AlN and GaN doped with rare earth elements (2006)
  • Author(s): S. W. Choi, S. Emura, S. Kimura, M. S. Kim, Y. K. Zhou, N. Teraguchi, A. Suzuki, A. Yanase, and H. Asahi
  • Journal Title: J. Alloys and Compounds 408-412 Pages: 717-720
  • Peer Reviewed
• [Presentation] Ferromagnetism and Luminescence of Diluted Magnetic Semiconductors GaGdN and AlGdN (2008)
  • Author(s): S. Emura, M. Takahashi, H. Tambo, T. Nakamura, Y.K Zhou, S. Hasegawa and H. Asahi
  • Organizer: 2008 Materials Research Society Fall Meeting
  • Place of Presentation: ボストン(米国)(招待講演)
  • Year and Date: 2008-12-02
• [Presentation] Growth and characterization of transition-metal and rare-earth doped III-nitride based magnetic semiconductors for nano-spintronics(招待講演) (2008)
  • Author(s): H. Asahi, S. Hasegawa, S. Emura and Y. K. Zhou
  • Organizer: 4th Handai Nanoscinece and Nanotechnology International Symposium
  • Place of Presentation: 大阪
  • Year and Date: 2008-10-01
• [Presentation] Crystal growth and characterization of GaCrN nanorods on Si substrate (2008)
  • Author(s): H. Tambo, S. Kimura, Y. Yamauchi, Y. Hiromura, S. Emura, S. Hasegawa and H. Asahi
  • Organizer: The 2nd International Symposium on Growth of III-Nitrides
  • Place of Presentation: 伊豆
  • Year and Date: 2008-10-01
• [Presentation] Magnetic properties of GaGdN studied by SQUID and SX-MCD (2008)
  • Author(s): M. Takahashi, Y. K. Zhou, S. Emura, T. Nakamura, S. Hasegawa and H Asahi
  • Organizer: 5th International Conference on Physics and Applications of Spin-Related Phenomena in Semiconductors
  • Place of Presentation: Foz do Iguacu(ブラジル)
  • Year and Date: 2008-08-05
• [Presentation] Annealing effect in GaDyN on optical and magnetic properties (2008)
  • Author(s): Y. K. Zhou, M. Takahashi, S. Emura, S. Hasegawa and H. Asahi
  • Organizer: 5th International Conference on Physics and Applications of Spin-Related Phenomena in Semiconductors
  • Place of Presentation: Foz do Iguacu(ブラジル)
  • Year and Date: 2008-08-04
• [Presentation] Structural properties of AlCrN (2008)
  • Author(s): S. Kimura, K. Tokuda, Y. K. Zhou, S. Emura, S. Hasegawa and H. Asahi
  • Organizer: GaCrN and InCrN, 15th International Conference on Molecular Beam Epitaxy
  • Place of Presentation: バンクーバー(カナダ)
  • Year and Date: 2008-08-04
• [Presentation] Third magnetic phase of GaGdN detected by SX-MCD (2008)
  • Author(s): M. Takahashi, Y. Hiromura, S. Emura, T. Nakamura Y. K. Zhou, S. Hasegawa and H Asahi
  • Organizer: 29th International Conference on Physics of Semiconductors
  • Place of Presentation: リオデジャネイロ(ブラジル)
  • Year and Date: 2008-07-29
• [Presentation] Orbital ordering on dilute Cr3+ ions doped in GaN (2008)
  • Author(s): S. Emura, S. Kimura, K. Tokuda, Y. K. Zhou, S. Hasegawa and H Asahi
  • Organizer: 29th International Conference on Physics of Semiconductors
  • Place of Presentation: リオデジャネイロ(ブラジル)
  • Year and Date: 2008-07-29
• [Presentation] Formation of aligned CrN nano-clusters in Cr-delta-doped GaN (2008)
  • Author(s): Y. K. Zhou, S. Kimura, S. Emura, S. Hasegawa and H. Asahi
  • Organizer: International Conference on Quantum Simulators and Design 2008
  • Place of Presentation: 東京
  • Year and Date: 2008-06-01
• [Presentation] Growth and characterization of InCrN and (In, Ga, Cr)N diluted magnetic semiconductors (2007)
  • Author(s): S. Kimura, S. Emura, Y. Hiromura, Y. K. Zhou, S. Hasegawa and H. Asahi
  • Organizer: 7th International Conference on Nitride Semiconductors
  • Place of Presentation: ラスベガス(米国)
  • Year and Date: 2007-09-19
• [Presentation] High Gd concentration GaGdN grown at low temperature (2007)
  • Author(s): Y. K. Zhou, S.W. Choi, S. Kimura, S. Emura, S. Hasegawa and H. Asahi
  • Organizer: SpinTech-IV
  • Place of Presentation: ハワイ(米国)
  • Year and Date: 2007-06-21
• [Presentation] MBE Growth and Characterization of Rare-Earth Doped Nitride Semiconductors for Spintronics (2007)
  • Author(s): H. Asahi, Y.K. Zhou, S. Emura and S. Hasegawa
  • Organizer: E-MRS2007
  • Place of Presentation: ストラスブルグ(フランス)(招待講演)
  • Year and Date: 2007-05-29
• [Presentation] Evolution of Cr-doped and Gd-doped GaN layers grown at low temperatures (2006)
  • Author(s): Y. K. Zhou, S.W. Choi, S. Kimura, S. Emura, S. Hasegawa and H. Asahi
  • Organizer: IUMRS International Conference in Asia 2006【最優秀論文賞】
  • Place of Presentation: チェジュ島(韓国)
  • Year and Date: 2006-09-12
• [Presentation] Magnetic properties of Gd-doped GaN single layer and GaGdN short period superlattices grown by RF-MBE (2006)
  • Author(s): S. W. Choi, Y. K. Zhou, S. Kimura, S. Emura, S. Hasegawa and H. Asahi
  • Organizer: IUMRS International Conference in Asia 2006
  • Place of Presentation: チェジュ島(韓国)
  • Year and Date: 2006-09-12
• [Presentation] Electronic structure of ferromagnetic element Cr in DMS GaCrN observed in X-ray absorption spectra (2006)
  • Author(s): S. Emura, S. Kimura, M. Hashimoto, S. Kobayashi, S. W. Choi, M.S. Kim, Y. K. Zhou and H. Asahi
  • Organizer: IUMRS International Conference in Asia 2006
  • Place of Presentation: チェジュ島(韓国)
  • Year and Date: 2006-09-11
• [Presentation] Growth and Characterization of Ferromagnetic Cubic GaCrN (2006)
  • Author(s): S. Kimura, S. Kabayashi, Y. K. Zhou, S. Choi, S. Subashcandran, H. Ofuchi, M. Ishimaru, Y. Hirotsu, S. Emura, S. Hasegawa and H. Asahi
  • Organizer: 14th International Conference on Molecular Beam Epitaxy
  • Place of Presentation: 東京
  • Year and Date: 2006-09-04
• [Presentation] Electronic State and Local Structure Analysis of GaGdN by HX-PES and XAFS (2006)
  • Author(s): S. Emura, S.W. Choi, J.J. Kim, S. Kimura, S. Kobayashi, Y. K. Zhou, K. Kobayashi, H. Asahi, N. Teraguchi and A. Suzuki
  • Organizer: International Conference on Physics and Applications of Spin Related Phenomena in Semiconductors
  • Place of Presentation: 仙台
  • Year and Date: 2006-08-17
• [Presentation] Magnetic properties of GaGdN/GaN superlattices grown by RF-MBE (2006)
  • Author(s): S. W. Choi, Y. K. Zhou, S. Kimura, S. Emura, S. Hasegawa, and H. Asahi
  • Organizer: International Conference on Physics and Applications of Spin Related Phenomena in Semiconductors
  • Place of Presentation: 仙台
  • Year and Date: 2006-08-17
• [Presentation] Cr atom alignment in Cr-delta-doped GaN (2006)
  • Author(s): S. Kimura, S. Emura, H. Ofuchi, Y. Nakata, Y. K. Zhou, C. W. Choi, Y. Yamauchi, S. Hasegawa and H. Asahi
  • Organizer: The XIII International Conference on XAFS
  • Place of Presentation: スタンフォード(米国)
  • Year and Date: 2006-07-13
• [Book] 薄膜ハンドブック (2008)
  • Author(s): 朝日一
  • Total Pages: 10-14
  • Publisher: オーム社
• [Remarks]
  • URL: http://www.sanken.osaka-u.ac.jp/labs/pem/
• [Patent(Industrial Property Rights)] 磁性制御方法 (2006)
  • Inventor(s): 江村修一、朝日一、周逸凱
  • Industrial Property Rights Holder: 大阪大学
  • Industrial Property Number: 特許,特願2006-319153
  • Filing Date: 2006-11-27
• [Patent(Industrial Property Rights)] 強磁性材料 (2006)
  • Inventor(s): 周逸凱、朝日一
  • Industrial Property Rights Holder: 大阪大学
  • Industrial Property Number: 特願2006-294577
  • Filing Date: 2006-10-30