Heusler alloy - Carbon nanotube junctions as a probe for detectinglocal spin states

2008 Fiscal Year Final Research Report

• Project/Area Number: 19760225
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Single-year Grants
• Research Field: Electron device/Electronic equipment
• Research Institution: Hokkaido University
• Principal Investigator: MATSUDA Kenichi Hokkaido University, 大学院情報科学研究科, 助教授 (80360931)
• Project Period (FY): 2007 – 2008
• Keywords: スピントロニクス / ハーフメタル強磁性体 / ホイスラー合金 / カーボンナノチューブ

Research Abstract

本研究の成果は、電極として採用したハーフメタル系強磁性材料Co2MnSi、Co2MnGe、Co2Cr0.6Fe0.4Al のエピタキシャル成長に成功したこと、またその高いスピン偏極率を、強磁性トンネル接合の電気伝導特性を通して明らかにしたことである。電子スピン検出を行うには、高い偏極率を有する強磁性材料を単結晶成長することが重要であり、本研究においてCo 系ホイスラー合金の潜在的な能力の高さを示すことができた。

Research Products

• [Journal Article] Tunneling anisotropic magnetoresistance in epitaxial CoFe/n-GaAs junctions (2009)
  • Author(s): T. Uemuara, Y. Imai, M. Harada, K.-I. Matsuda, and M. Yamamoto
  • Journal Title: Appl. Phys. Lett. vol. 94 Pages: 182502-1-182502-3
  • Peer Reviewed
• [Journal Article] Transport properties of Nb/PdNi bilayers and Nb/PdNi/Nb Josephson junctions (2009)
  • Author(s): K.-I. Matsuda, Y. Akimoto, T. Uemura and M. Yamamoto
  • Journal Title: J. Physics: Conference Series vol. 150 Pages: 0521551-1-0521551-4
  • Peer Reviewed
• [Journal Article] Spin-dependent tunneling characteristics of fully epitaxial magnetic tunnel junctions with a Heusler alloy Co2MnGe thin film and a MgO barrier (2009)
  • Author(s): T. Taira, T. Ishikawa, N. Itabashi, K.-I. Matsuda, T. Uemura, and M. Yamamoto
  • Journal Title: J. Phys. D: Applied Phys. vol. 42 Pages: 084015-1-084015-9
  • Peer Reviewed
• [Journal Article] Half-metallic electronic structure of Co_2MnSi electrodes in fully epitaxial Co_2MnSi/MgO/Co_2MnSi magnetic tunnel junctions proved by tunneling spectroscopy (2009)
  • Author(s): T. Ishikawa, N. Itabashi, T. Taira, K.-I. Matsuda, T. Uemura, and M. Yamamoto
  • Journal Title: J. Appl. Phys. vol. 105 Pages: 07B110-1-07B110-6
  • Peer Reviewed
• [Journal Article] Critical role of interface states for spin-dependent tunneling in half-metallic Co_2MnSi-based magnetic tunnel junctions investigated by tunneling spectroscopy (2009)
  • Author(s): T. Ishikawa, N. Itabashi, T. Taira, K.-. Matsuda, T. Uemura, and M. Yamamoto
  • Journal Title: Appl. Phys. Lett. vol. 94 Pages: 092503-1-092503-3
  • Peer Reviewed
• [Journal Article] Influence of annealing on spin-dependent tunneling characteristics of fully epitaxial Co_2MnGe / MgO /Co_<50>Fe_<50> magnetic tunnel junctions (2009)
  • Author(s): T. Taira, T. Ishikawa, N. Itabashi, K.-I. Matsuda, T. Uemura, and M. Yamamoto
  • Journal Title: Appl. Phys. Lett. vol.94 Pages: 072510-1-072510-3
  • Peer Reviewed
• [Journal Article] Fabrication and Characterization of Fully Epitaxial Magnetic Tunnel Junction Field Sensors using a Co2MnSi Thin Film (2008)
  • Author(s): M. Masuda, T. Uemura, K.-I. Matsuda and M. Yamamoto
  • Journal Title: IEEE Transactions on Magnetics vol.44 Pages: 3996-399
  • Peer Reviewed
• [Journal Article] Epitaxial growth and characterization of Co_2MnSi thin films on GaAs with MgO interlayer (2008)
  • Author(s): T. Uemura, Y. Imai, S. Kawagishi, K.-I. Matsuda, and M. Yamamoto
  • Journal Title: Physica E: Low-dimensional Systems and Nanostructures vol. 40
  • Peer Reviewed
• [Journal Article] Fabrication of fully epitaxial Co_2MnSi/MgO/Co_2MnSi magnetic tunnel junctions (2008)
  • Author(s): T. Ishikawa, S. Hakamata, K.-I. Matsuda, T. Uemura, and M. Yamamoto
  • Journal Title: J. Appl. Phys. vol. 103 Pages: 07A919-1-07A919-3
  • Peer Reviewed
• [Journal Article] Magnetic and transport properties of superconductor / ferromagnetic bilayer microbridges (2008)
  • Author(s): K.-I. Matsuda, Y. Akimoto, T. Uemura, and M. Yamamoto
  • Journal Title: J. Appl. Phys. (and selected for the February 15, 2008 issue of Virtual Journal of Applications of Superconductivity) vol. 103 Pages: 07C711-1-07C711-3
• [Journal Article] Structural, magnetic and electrical properties of Co_2MnSi / MgO / n-GaAs tunnel junction (2008)
  • Author(s): S. Kawagishi, T. Uemura, Y. Imai, K.-I. Matsuda, and M. Yamamoto
  • Journal Title: J. Appl. Phys. vol.103 Pages: 07A703-1-07A703-3
  • Peer Reviewed
• [Journal Article] Structural and magnetic properties of Co_2Cr_<0.6>Fe_<0.4>Al thin films epitaxially grown on GaAs substrate with MgO interlayer (2007)
  • Author(s): T. Uemura, T. Yano, K.-I. Matsuda, and M. Yamamoto
  • Journal Title: Thin Solid Films vol. 515 Pages: 8013-8016
  • Peer Reviewed
• [Journal Article] Fabrication of Epitaxial Magnetic Tunnel Junctions with a Co_2Cr_<0.>6Fe_<0.4>Al Thin Film and Their Tunnel Magnetoresistance Characteristics (2007)
  • Author(s): T. Marukame, T. Ishikawa, S. Hakamata, K.-I. Matsuda, T. Uemura, and M. Yamamoto
  • Journal Title: J. Magn. Soc. Jpn. vol. 31 Pages: 344-350
  • Peer Reviewed
• [Journal Article] Fabrication of Fully Epitaxial Co_2Cr_<0.6>Fe_<0.4>Al / MgO / Co_2Cr_<0.6>Fe_<0.4>Al Magnetic Tunnel Junctions (2007)
  • Author(s): T. Marukame, T. Ishikawa, S. Hakamata, K.-I. Matsuda, T. Uemura, and M. Yamamoto
  • Journal Title: IEEE Trans. On Magn. vol.43 Pages: 2782-2784
  • Peer Reviewed
• [Journal Article] Magnetic and Transport Properties of Nb/PdNi Bilayers (2007)
  • Author(s): K.-I. Matsuda, H. Niwa, Y. Akimoto, T. Uemura, and M. Yamamoto
  • Journal Title: IEEE Trans. On Appl. Supercond. vol. 17 Pages: 3529-3532
  • Peer Reviewed
• [Journal Article] Four-state Magnetoresistance in Epitaxial CoFe-based Magnetic Tunnel Junction (2007)
  • Author(s): T. Uemura, T. Marukame, K.-I. Matsuda, and M.Yamamoto
  • Journal Title: IEEE Trans. On Magn. vol. 43 Pages: 2791-2793
  • Peer Reviewed
• [Journal Article] Improved tunnel magnetoresistance characteristics of magnetic tunnel junctions with a Heusler alloy thin film of Co2MnGe and a MgO tunnel barrier (2007)
  • Author(s): S. Hakamata, T. Ishikawa, T. Marukame, K.-I. Matsuda, T. Uemura, M. Arita, and M. Yamamoto
  • Journal Title: J. Appl. Phys. vol. 101 Pages: 09J513-1-09J513-3
  • Peer Reviewed
• [Presentation] エピタキシャルCoFe/n-GaAs 接合における磁気抵抗特性 (2009)
  • Author(s): 今井洋介,原田雅亘,植村哲也,松田健一, 山本眞史
  • Organizer: 2009 年 (平成21 年) 春季第56 回応用物理学会関係連合講演会
  • Place of Presentation: 31a-L-7,つくば市,筑波大学
  • Year and Date: 20090330-0402
• [Presentation] 強磁性細線中を伝搬する磁壁の構造および運動のTMR 検出のシミュレーション (2009)
  • Author(s): 澤田圭佑,植村哲也,増田昌洋,松田健一,山本眞史
  • Organizer: 2009 年 (平成21 年)春季第56 回応用物理学会関係連合講演会
  • Place of Presentation: 31a-L-7,つくば市、筑波大学
  • Year and Date: 20090330-0402
• [Presentation] エピタキシャルCoFe/n-GaAs 接合における磁気抵抗特性 (2009)
  • Author(s): 今井洋介,原田雅亘,植村哲也,松田健一, 山本眞史
  • Organizer: The 13th Symposiumu on the Physics and Application of Spin-Related Phenomena in Semiconductors (PASPS13)
  • Place of Presentation: 仙台市,東北大学
  • Year and Date: 20090127-28
• [Presentation] Co_2Cr_<0.6>Fe_<0.4>Al / MgO / Co_<50>Fe_<50> 強磁性トンネル接合のコンダクタンス特性に対するアニールの影響 (2009)
  • Author(s): 米村和希,板橋直樹,松田健一,植村哲也,山本眞史
  • Organizer: 2009 年 (平成21 年) 第44 回応用物理学会北海道支部学術講演会 講演予稿集B-16
  • Place of Presentation: 函館市,サン・リフレ函館
  • Year and Date: 20090108-09
• [Presentation] Co_2Cr_<0.6>Fe_<0.4>Al/MgO/Co_2Cr_<0.6>Fe_<0.4>Al 強磁性トンネル接合のスピン依存コンダクタンス特性 (2009)
  • Author(s): 板橋直樹,石川貴之,米村和希,松田健一, 植村哲也, 山本眞史
  • Organizer: 2009 年 (平成21 年) 第44 回応用物理学会北海道支部学術講演会 講演予稿集 B-17
  • Place of Presentation: 函館市,サン・リフレ函館
  • Year and Date: 20090108-09
• [Presentation] ホイスラー合金薄膜を上部フリー層に用いた微細MTJ の作製と評価 (2009)
  • Author(s): 増田昌洋,澤田圭佑,植村哲也,松田健一,山本眞史
  • Organizer: 2009 年 (平成21 年) 第44 回応用物理学会北海道支部学術講演会 B-21
  • Place of Presentation: 函館市,サン・リフレ函館
  • Year and Date: 20090108-09
• [Presentation] CoFe/n-GaAs/CoFe 横型接合における磁気抵抗特性 (2009)
  • Author(s): 今井洋介,原田雅亘,植村哲也,松田健一,山本眞史
  • Organizer: 2009 年(平成21 年) 第44 回応用物理学会北海道支部学術講演会 B-22
  • Place of Presentation: 函館市,サン・リフレ函館
  • Year and Date: 20090108-09
• [Presentation] Co_2MnSi 細線電極における磁壁構造に依存したトンネル磁気抵抗のシミュレーション (2009)
  • Author(s): 澤田圭佑,増田昌洋,植村哲也,松田健一,山本眞史
  • Organizer: 2009 年 (平成21 年) 第44 回応用物理学会北海道支部学術講演会 B-23
  • Place of Presentation: 函館市,サン・リフレ函館
  • Year and Date: 20090108-09
• [Presentation] ハーフメタル系強磁性体(Co_2Cr_<0.6>Fe_<0.4>Al)/超伝導体(NbN)二層薄膜のエピタキシャル成長 (2009)
  • Author(s): 井悟嗣,石川貴之,松田健一,植村哲也,山本眞史
  • Organizer: 2009 年(平成21 年) 第44 回応用物理学会北海道支部学術講演会 講演予稿集 B-24
  • Place of Presentation: 函館市,サン・リフレ函館
  • Year and Date: 20090108-09
• [Presentation] Tunneling spectroscopy of fully epitaxial CO_2MnSi/MgO/CO_2MnSi magnetic tunnel junctions (2008)
  • Author(s): T. Ishikawa, N. Itabashi, T. Taira, K.-I. Matsuda, T. Uemura and M. Yamamoto
  • Organizer: 2008 Material Research Society (MRS) Fall Meeting, L5.1
  • Place of Presentation: Boston, MA, USA
  • Year and Date: 20081201-05
• [Presentation] Tunneling conductance characteristics for Co_2Cr_<0.6>Fe_<0.4>Al /MgO / Co_2Cr_<0.6>Fe_<0.4>Al magnetic tunnel junctions (2008)
  • Author(s): N. Itabashi, T. Ishikawa, K. Yonemura, K.-I. Matsuda, T. Uemura and M. Yamamoto
  • Organizer: 2008 Material Research Society (MRS) Fall Meeting, L2.10
  • Place of Presentation: Boston, MA, USA
  • Year and Date: 20081201-05
• [Presentation] Spin-polarized tunneling in fully epitaxial magnetic tunnel junctions with Heusler alloy thin films and a MgO barrier (2008)
  • Author(s): M. Yamamoto, T. Ishikawa, K.-I. Matsuda, and T. Uemura
  • Organizer: 2008 Material Research Society (MRS) Fall Meeting, L2.6
  • Place of Presentation: Boston, MA, USA
  • Year and Date: 20081201-05
• [Presentation] Tunnel magnetoresistance characteristics of post-deposition-annealed CO_2MnGe / MgO / CoFe tunnel junctions (2008)
  • Author(s): T. Taira, T. Ishikawa, K.-I. Matsuda,T. Uemura and M. Yamamoto
  • Organizer: 2008 Material Research Society (MRS) Fall Meeting, Boston, L2.1
  • Place of Presentation: Boston, MA, USA
  • Year and Date: 20081201-05
• [Presentation] Spin-dependent electronic structures of Co_2Cr_<0.6>Fe_<0.4>Al electrodes investigated through tunneling spectroscopy (2008)
  • Author(s): N. Itabashi, T. Ishikawa, K. Yonemura, K.-I. Matsuda, T. Uemura and M. Yamamoto
  • Organizer: 53rd Magnetism and Magnetic Materials Conference, GT-03
  • Place of Presentation: Austin, TX, USA
  • Year and Date: 20081110-15
• [Presentation] Tunneling spectroscopy of Co_2Cr_<0.6>Fe_<0.4>Al/MgO/CoFe magnetic tunnel junctions (2008)
  • Author(s): K. Yonemura, T. Ishikawa, N. Itabashi, K.-I. Matsuda, T. Uemura and M. Yamamoto
  • Organizer: 53rd Magnetism and Magnetic Materials Conference, ED-07
  • Place of Presentation: Austin, TX, USA
  • Year and Date: 20081110-15
• [Presentation] Spin-dependent tunneling characteristics of CO_2MnGe/MgO/CoFe tunnel junctions (2008)
  • Author(s): T. Taira, T. Ishikawa, K.-I. Matsuda, T. Uemura, and M. Yamamoto
  • Organizer: 53rd Magnetism and Magnetic Materials Conference, DD-02
  • Place of Presentation: Austin, TX, USA
  • Year and Date: 20081110-15
• [Presentation] Half-metallic electronic structure of CO_2MnSi electrodes proved by tunneling spectroscopy (2008)
  • Author(s): T. Ishikawa, N. Itabashi, T. Taira, K.-I. Matsuda, T. Uemura and M. Yamamoto
  • Organizer: 53rd Magnetism and Magnetic Materials Conference, DD-07
  • Place of Presentation: Austin, TX, USA
  • Year and Date: 20081110-15
• [Presentation] Fabrication of fully epitaxial magnetic tunnel junctions with half-metallic Heusler alloy thin films and a MgO tunnel barrier (2008)
  • Author(s): M. Yamamoto, T. Uemura, and K.-I. Matusda
  • Organizer: The 10th Int'l Joint Symposium between Hokkaido University and Chungnam National University
  • Place of Presentation: Sapporo
  • Year and Date: 20081022-24
• [Presentation] Spin-dependent tunneling spectroscopy of fully epitaxial magnetic tunnel junctions with Heusler alloy Co_2Cr_<0.6>Fe_<0.4>Al electrodes and a MgO barrier (2008)
  • Author(s): N. Itabashi, T. Ishikawa, K.-I. Matsuda, T. Uemura, and M. Yamamoto,
  • Organizer: 25th Int'l Conf. on Low Temp. Physics, PD-Mo244
  • Place of Presentation: Amsterdam, The Netherlands
  • Year and Date: 20080806-13
• [Presentation] Transport Properties of Nb/PdNi bilayers and Nb/PdNi/Nb Josephson junctions (2008)
  • Author(s): K.-I. Matsuda, Y. Akimoto, T. Uemura, and M. Yamamoto
  • Organizer: 25th Int'l Conf. on Low Temp. Physics, p. 25, PB-Th118
  • Place of Presentation: Amsterdam, The Netherlands
  • Year and Date: 20080806-13
• [Presentation] Spin-dependent tunneling conductance in fully epitaxial CO_2MnSi/MgO/CO_2MnsI tunnel junctions (2008)
  • Author(s): T. Ishikawa, N. Itabashi, K.-I. Matsuda, T. Uemura, and M. Yamamoto
  • Organizer: Technical Digests of IEEE Int'l Magnetics Conf. Europe 2008, AC-07
  • Place of Presentation: Madrid, Spain
  • Year and Date: 20080504-08
• [Presentation] Fabrication and characterization of magnetic tunnel junction field sensors with a CO_2MnSi thin film (2008)
  • Author(s): M. Masuda, T. Uemura, K.-I. Matsuda and M. Yamamoto
  • Organizer: Technical Digests of IEEE Int'l Magnetics Conf. Europe 2008, BD-04
  • Place of Presentation: Madrid, Spain
  • Year and Date: 20080504-08
• [Presentation] Heusler alloy-based fully epitaxial magnetic tunnel junctions with a MgO barrier (2008)
  • Author(s): M. Yamamoto, T. Uemura, and K.-I. Matsuda
  • Organizer: 2008 RCIQE Int'l Seminar on "Advanced Semiconductor Materials and Devices"
  • Place of Presentation: Sapporo, Japan
  • Year and Date: 20080303-04
• [Presentation] Magnetic and transport properties of superconductor / ferromagnet bilayer microbridges (2007)
  • Author(s): K.-I. Matsuda, Y. Akimoto, T. Uemura, and M. Yamamoto
  • Organizer: 52nd Magnetism and Magnetic Materials Conference, HQ-10
  • Place of Presentation: Tampa, Florida, USA
  • Year and Date: 20071105-09
• [Presentation] Highly spin-polarized tunneling in Heusler alloy-based fully epitaxial magnetic tunnel junctions with a MgO tunnel barrier (2007)
  • Author(s): M. Yamamoto, T. Marukame, T. Ishikawa, K.-I. Matsuda, and T. Uemura
  • Organizer: 52nd Magnetism and Magnetic Materials Conference, DB-01
  • Place of Presentation: Tampa, Florida, USA
  • Year and Date: 20071105-09
• [Presentation] Oscillations in tunneling resistance as a function of MgO barrier thickness in fully epitaxial magnetic tunnel junctions of Co_2Cr_<0.6>Fe_<0.4>Al / MgO / Co_<50> Fe_<50> (2007)
  • Author(s): M. Yamamoto, T. Marukame, T. Ishikawa, K.-I. Matsuda, and T. Uemura
  • Organizer: 52nd Magnetism and Magnetic Materials Conference, AB-11
  • Place of Presentation: Tampa, Florida, USA
  • Year and Date: 20071105-09
• [Presentation] Spin-dependent tunneling in fully epitaxial CO_2MnSi / MgO / CO_2MnSi magnetic tunnel junctions (2007)
  • Author(s): T. Ishikawa, S. Hakamata, K.-I. Matsuda, T. Uemura, and M. Yamamoto
  • Organizer: 52nd Magnetism and Magnetic Materials Conference, AB-07
  • Place of Presentation: Tampa, Florida, USA
  • Year and Date: 20071105-09
• [Presentation] Electrical characterization of epitaxial CO_2MnSi / MgO / n-GaAs tunnel junctions (2007)
  • Author(s): S. Kawagishi, T. Uemura, Y. Imai, K.-I. Matsuda, and M. Yamamoto
  • Organizer: 52nd Magnetism and Magnetic Materials Conference, AG-09
  • Place of Presentation: Tampa, Florida, USA
  • Year and Date: 20071105-09
• [Presentation] Epitaxial growth and characterization of CO_2MnSi thin films on GaAs with MgO interlayer (2007)
  • Author(s): T. Uemura, T. Yano, Y. Imai, K.-I. Matsuda, and M. Yamamoto
  • Organizer: The 13th Int'l Conf. on Modulated Semiconductor Structures
  • Place of Presentation: Genova, Italy
  • Year and Date: 20070715-20
• [Book] Advances in Solid State Physics 47 (Highly Spin-Polarized Tunneling in Fully Epitaxial Magnetic Tunnel Junctions with a Co-Based Full-Heusler Alloy Thin Film and a MgO Barrier) (R.Haug (Ed.)) (pp. 105-116) (2008)
  • Author(s): M. Yamamoto, T. Marukame, T. Ishikawa, K.-I. Matsuda, and T. Uemura
  • Total Pages: 105-116
  • Publisher: Springer Berlin /Heidelberg