量子ビットへの応用を目指した強磁性体/高温超伝導体接合作製に関する基礎研究

• Project/Area Number: 05J00518
• Research Category: Grant-in-Aid for JSPS Fellows
• Allocation Type: Single-year Grants
• Section: 国内
• Research Field: Thin film/Surface and interfacial physical properties
• Research Institution: National Institute for Materials Science
• Principal Investigator: 田中 博美 National Institute for Materials Science, 共用基盤部門, 特別研究員(PD)
• Project Period (FY): 2005 – 2007
• Project Status: Completed (Fiscal Year 2007)
• Budget Amount: ¥3,300,000 (Direct Cost: ¥3,300,000); Fiscal Year 2007: ¥1,100,000 (Direct Cost: ¥1,100,000); Fiscal Year 2006: ¥1,100,000 (Direct Cost: ¥1,100,000); Fiscal Year 2005: ¥1,100,000 (Direct Cost: ¥1,100,000)
• Keywords: 界面非破壊評価 / 放射光 / ASGQP / 垂直ブリッジマン法

Research Abstract

良質な界面を有する強磁性体/高温超伝導体の接合作製についての基礎技術開発を行った。具体的にはLa_<0.85>Ba_<0.15>MnO_3/YBa_2Cu_3O_y接合をパルスレーザー堆積法により作製し、得られた接合の界面ナノ領域における化学結合・電子状態を明らかにする為、硬X線励起光電子分光を用いたdepthプロファイルを行った。その結果、YBa_2Cu_3O_yにおいて観測されるCu-2p内殻光電子スペクトルのサテライト強度が接合界面近傍において著しく減少していることが分かった。又、一方でLa_<0.良質な界面を有する強磁性体/高温超伝導体の接合作製についての基礎技術開発を行った。具体的にはLa_<0.85>Ba_<0.15>MnO_3の構成元素であるMn及びBaの内殻光電子スペクトルも接合界面近傍においてケミカルシフトを起こし、それに伴いブロードニングが生じていることが分かった。これは接合界面近傍において異なる価数状態が混在し、キャリア状態が変化していることを示唆する。詳細な解析の結果、La_<0.85>Ba_<0.15>MnO_3/YBa_2Cu_3O_yの接合界面にはCuの価数が大きく低下した非超伝導層、及びスピン偏極率が低下している強磁性体層が存在していることが明らかとなった。この結果から、非超伝導層や低スピン偏極率層が接合界面に存在しない良質な接合を作製する為には、成膜時の作製条件等を工夫する必要があることが分かった。

Research Products

• [Journal Article] Bi_2Sr_2CaCu_2O_y single crystals grown using various crucibles (2007)
  • Author(s): S. Adachi
  • Journal Title: Physica C 463-465 Pages: 449-451
  • Peer Reviewed
• [Journal Article] Growth of Bi_2Sr_2Ca_<n-1>Cu_nO_y superconductor films in off-axis geometry by rf magnetron sputtering method with multi-target (2007)
  • Author(s): T. Yamane
  • Journal Title: Proceedings of the 9th International Symposium on Sputtering and Plasma Processes 9 Pages: 81-83
• [Journal Article] Effect of Al metal deposition on growth of Bi-based whiskers in a glassy quenched platelet method (2007)
  • Author(s): T. Ishigaki
  • Journal Title: Physica C 463-465 Pages: 436-438
  • Peer Reviewed
• [Journal Article] Effects of Al_2O_3 grain sizes on growth of Bi-based superconducting whiskers using ASGQP method (2006)
  • Author(s): H.Tanaka
  • Journal Title: Proceedings of the 3rd Asia-Pacific Conference of Transducers and Micro-Nano Technology Vol.3 Pages: 1-4
• [Journal Article] Bi_2Sr_2CaCu_2O_y single crystal growth in Bridgman-Stockbarger method using different oxygen partial pressure (2006)
  • Author(s): Y.Echizen
  • Journal Title: Physica C Vol.445-448・Pt.1 Pages: 455-458
• [Journal Article] Composition control of Bi_2Sr_2Ca_n-1O_y superconducting thin films by rf magnetron sputtering method (2006)
  • Author(s): Y.Yamane
  • Journal Title: Proceedings of XXIInd Int. Symp. on Discharges and Electrical Insulation in Vacuum 2006 Vol.22・No.2 Pages: 592-595
• [Journal Article] Enlargement effect of the crucible size on Bi_2Sr_2CaCu_2O_y single crystals grown by a modified vertical Bridgman method (2005)
  • Author(s): H.Tanaka
  • Journal Title: IEEE Transactions on Applied Superconductivity Vol.15・No.2 Pages: 3133-3136
• [Journal Article] Elucidation of Enhancement mechanism of Critical Current Density in Bi_2Sr_2Ca_<n-1>Cu_nO_y Superconducting Whisker by SR-XPS and HRTEM (2005)
  • Author(s): H.Tanaka
  • Journal Title: 日本学術振興会 マイクロビームアナリシス第141委員会 第120回研究会,研究会資料 Vol.120 Pages: 64-69
• [Journal Article] Growth of Bi-2212 single crystals by a Vertical Bridgman method using large crucibles (2005)
  • Author(s): Y.Echizen
  • Journal Title: Physica C Vol.426-431・Pt.1 Pages: 583-587
• [Journal Article] Bi_2Sr_2CaCu_2O_y single crystals grown using various crucibles
  • Author(s): S.Adachi
  • Journal Title: Physica C (in press)
• [Journal Article] Effect of Al metal deposition on growth of Bi-based whiskers in a glassy quenched platelet method
  • Author(s): T.Ishigaki
  • Journal Title: Physica C (in press)
• [Journal Article] Bi_2Sr_2CaCu_2O_y single crysiai growth in Bridgman-Stockbarger method using different oxygen partial pressure
  • Author(s): Y.Echizen
  • Journal Title: Physica C in press
• [Presentation] Growth of Bi_2Sr_2Ca_<n-1>Cu_nO_y superconductor films in off-axis geometry by rf magnetron sputtering method with multi-target (2007)
  • Author(s): T. Yamane
  • Organizer: the 9th International Symposium on Sputtering and Plasma Processes
  • Place of Presentation: Kanazawa, Japan
• [Presentation] Growth of high quality Bi-2212 single crystals by a horizontal Bridgman method in various atmospheres (2007)
  • Author(s): M. Fujiwara
  • Organizer: 8th European Conference on Applied Superconductivity
  • Place of Presentation: Brussels Expo., Brusseles, Belgium
• [Presentation] Superconducting Property of Bi-Based Whiskers Grown by ASGQP Method (2007)
  • Author(s): S. Honda
  • Organizer: the 4th International Conference on Materials for Advanced Technologies
  • Place of Presentation: the Suntec Singapore International Convention and Exhibition Centre, Singapore
• [Presentation] Effect of Al-metal deposition on growth of Bi-Based Whiskers in a glassy quenched (2007)
  • Author(s): T. Ishigaki
  • Organizer: 8th European Conference on Applied Superconductivity
  • Place of Presentation: Brussels Expo., Brusseles, Belgium
• [Presentation] Annealing effect on Bi_2Sr_2CaCu_2O_y single crystals in various atmospheres (2007)
  • Author(s): S. Adachi
  • Organizer: the 4th International Conference on Materials for Advanced Technologies
  • Place of Presentation: the Suntec Singapore International Convention and Exhibition Centre, Singapore
• [Presentation] Multipole effect of asymmetry parameter derived by angle-resolved XPS analysis using high energy SR (2007)
  • Author(s): H. Yoshikawa
  • Organizer: 12th European Conference on Applications of Surface and Interface Analysis
  • Place of Presentation: Fragey streamship, Brussels, Belgium
• [Patent(Industrial Property Rights)] 高温超伝導単結晶上での面内型ジョセフソン接合形成法 (2007)
  • Inventor(s): 田中 博美, 吉川 英樹
  • Industrial Property Rights Holder: 物質・材料研究機構
  • Industrial Property Number: 2007-230126
  • Filing Date: 2007-09-05