1996 Fiscal Year Annual Research Report

酸化物新物質の創製と機能の探索

Research Project

Project/Area Number	08044135
Research Institution	Tokyo Institute of Technology
Principal Investigator	山内尚雄東京工業大学, 応用セラミックス研究所, 教授 (50271581)
Co-Investigator(Kenkyū-buntansha)	SCHLOM Darre ペンシルバニア州立大学, 材料科学工学科, 助教授 KARPPINEN Ma ヘルシンキ工科大学, 無機分析研究所, 講師 NIINISTO Lau ヘルシンキ工科大学, 無機分析研究所, 教授末松久幸東京工業大学, 応用セラミックス研究所, 助手 (30222045) 川崎雅司東京工業大学, 応用セラミックス研究所, 助手 (90211862) 吉本護東京工業大学, 応用セラミックス研究所, 助教授 (20174998) 鯉沼秀臣東京工業大学, 応用セラミックス研究所, 教授 (70011187)
Keywords	レーザーMBE / 酸化物エピタキシ- / 原子層エピタキシ- / 高温超伝導 / 臨界温度 / ホールド-ピングルート / 高圧合成 / ボンド・バレンス・サム
Research Abstract	セラミックス薄膜の原子レベル制御技術について、特に基板最表面原子層の同定とレーザーMBEによる最表面原子層の変換技術を確立した。この結果、その表面上にヘテロエピタキシ-を行う際、界面形成反応が原子レベルで制御できるようになった。SrTiO3の湿式処理後の最表面原子層はTiO2面であるが、SrOを1原子層堆積すると、この表面はSrO最表面のSrTiO3とみなすことができる。さらにYBCOを堆積すると、SrO表面上では理想的なエピタキシ-が進行するのに対して、TiO2面上ではCuOの析出物が発生する。最表面原子層の違いは、成長様式を制御する根本的な要因であることを明らかにした。ペン州立大学のシュローム教授とはMBEの原子線流束を測定する光学的手法と酸化物薄膜用の新単結晶基板の探索に関する共同研究を行い、1%以下の精度で流束を測定する技術を確立し、La-Sr-Al-Ta-O系新単結晶物質の可能性を明らかにした。ヘルシンキ工科大のニ-ニスト教授とは、CVDとレーザーMBEにおいて原子層エピタキシ-の制御要因を整理し、その類似点と相違点を浮き彫りにした。今後は、自己制御性を取り入れる工夫について共同で研究を進める。銅酸化物高温超電導物質の超伝導発現機構について、結晶構造内の原子位置より超伝導発現に必須なホール量を算出するにあたって、ボンド・バレンス・サムを適用する手法を開発した。この手法を用いて計算を行ったところ、ホールはCuO2面内では銅ではなく酸素により多く存在していることがわかった。さらに、多くの枚数のCuO2面を持つ超伝導物質のホール量をCuO2面ごとに比較したところ、頂点酸素を持つ外側のCuO2面よりも内側のCuO2面により多くのホールが閉じこめられていることが判明した。ヘルシンキ工科大学のカルピネン博士とはLaCuO3の高圧合成を行った。また、このホール量算出の手法を用いて、これまで得られた超伝導物質のホール量を計算し、異なる臨界温度を持つ超伝導物質に対してそれぞれホール量を算出した。今後は、臨界温度を直接算出する方法の開発、CuO2面に隣接する異なる原子がホールド-ピングにどの程度寄与しているかについて、共同で研究を行う。

Research Products
(22 results)

All Other

All Publications (22 results)

[Publications] Hideomi KOINUMA: "Fabrication of Atomically Defined Oxide Films on Si by Laser Molecular Beam Epitaxy" Physica B. 227. 323-325 (1996)
[Publications] Hideomi KOINUMA: "Synthesis of Carbon Clusters and Thin Films by Low Temperature Plasma Chemical Vapor Deposition under Atmosperic" Pure & Appl.Chem.68. 1151-1154 (1996)
[Publications] Tatsuro MAEDA: "Molecular Layer-by-layer Growth of SrTiO3 and BaTiO3 Films by Laser Molecular Beam Epitaxy" Mat.Sci.Eng.B. 41. 134-137 (1996)
[Publications] Hyun-Kwon HA: "Structure and Electric Properties of TiO2 Films Prepared by Cold Plasma Torch under Atmsopheric Pressure" Mat.Sci.Eng.B. 41. 143-147 (1996)
[Publications] Kazuhiro TAKAHASHI: "Advanced Processing and Characterization of SrTiO3 Single Crystals and Bicrystals for High TC Superconducting Film Substrate" Mat.Sci.Eng.B. 41. 152-156 (1996)
[Publications] Hyun-Kwon HA: "Open Air Plasma Chemical Vapor Deposition of Highly Dielectric Amorphous TiO2 Films" Appl.Phys.Lett.68. 2965-2967 (1996)
[Publications] Mitsutaka MATSUSE: "Atomic Force Microscopy and Sanning Tunneling Microscopy Studies on the Growth Mechanism of a-Si:H Films on Graphite Substrate" J.Non-Crystalline Solids. 200. 787-791 (1996)
[Publications] Tatsuro MAEDA: "Two-dimensional Laser Molecular Beam Epitaxy and Carrier Modulation of Infinite-layer BaCuO2 Films" Physica C. 247. 142-146 (1996)
[Publications] Hideomi KOINUMA: "Pulsed Laser Processing of Carbon and Silicon Clusters and Thin Films" Fullerene Sci.Tech.4. 599-612 (1996)
[Publications] Mitsutaka MATSUSE: "Real-Space Investigation of Initial Growth Process of Hydrogenated Amorphous Silicon on a Graphite Substrate" Phys.Rev.B. 53. 12585-12588 (1996)
[Publications] Myung-Bok LEE: "Pulsed Laser Deposition of Epitaxial Ferroelectric Pb(Zr,Ti)O3 Films on Si(100)Substrate" Jpn.J.Appl.Phys.35. L574-L576 (1996)
[Publications] M.Karppinen: "Determination of Oxygen Contents and Metal Valences in Oxide Superconductors by Chemical Methods" Supercond.Sci.Technol.9. 121-135 (1996)
[Publications] M.Karppinen: "High-pressure Synthesis and Thermal Decomposition of LaCuO_321GC13:Mater.Sci.Engineering B" B41. 59-62 (1996)
[Publications] M.Karppinen: "Synthesis of Various LaCuO_<3-y> Phases by a High-pressure Technique and Subsequent Post-Annealing Treatments" Physica C. 264. 268-274 (1996)
[Publications] M.Karppinen: "Studies on the Oxygen Stoichiometry and Copper Valency in Superconducting Cuprates by Means of Chemical Analysis" International Symposium on Advances in Superconductivity:New Materials,Critical Currents & Devices,(September 17-20,1996,Tata Institute of Fundamental Research,Mumbai,India). in the press.
[Publications] M.Karppinen: "Control on the Copper Valence and Properties by Oxygen Content Adjustment in the LaCuO_<3-y> System(0≦y≦0.5)" J.Solid Chem.in the press.
[Publications] M.Karppinen: "Various Themogravimetric Approaches to Oxygen Stoichiometry in Superconducting and Related Cuprates" Proceedings of Themal Analysis Symposium(Univ.of Helsinki,November 1996).in the press.
[Publications] M.Karppinen: "Oxygen Stoichiometry and Copper Valency in Superconducting Cuprates Studied Chemical Methods" Advances in SuperRconductivity IX,Springer-Verlag,Tokyo,1997. in the press.
[Publications] T.Ito: "High-Pressure Synthesis of CuBa_2Ca_<n-1>Cu_nO_x(n=3,4)Superconductors without External Oxidizing Agents" Materials Science & Engineering B. in the press.
[Publications] K.Fujinami: "Ca Doping Effect on Superconductivity in(Yb_<1-x>Ca_x)(Ba_<0.8>Sr_<0.2>)_2Cu_3O_<6+z>" Materials Science & Engineering B. in the press.
[Publications] H.Suematsu: "Simultaneous EDS and EELS Studies on Carbon in CuBa_2Ca_3Cu_4O_x Superconductors" Materials Science & Engineering B. in the press.
[Publications] M.Kawano: "Peak Effect in Stoichiometric SmBa_2Cu_3O_y Samples" Materials Science & Engineering B. in the press.

1996 Fiscal Year Annual Research Report

酸化物新物質の創製と機能の探索

Principal Investigator

山内 尚雄 東京工業大学, 応用セラミックス研究所, 教授 (50271581)

Research Products

[Publications] Hideomi KOINUMA: "Fabrication of Atomically Defined Oxide Films on Si by Laser Molecular Beam Epitaxy" Physica B. 227. 323-325 (1996)

[Publications] Hideomi KOINUMA: "Synthesis of Carbon Clusters and Thin Films by Low Temperature Plasma Chemical Vapor Deposition under Atmosperic" Pure & Appl.Chem.68. 1151-1154 (1996)

[Publications] Tatsuro MAEDA: "Molecular Layer-by-layer Growth of SrTiO3 and BaTiO3 Films by Laser Molecular Beam Epitaxy" Mat.Sci.Eng.B. 41. 134-137 (1996)

[Publications] Hyun-Kwon HA: "Structure and Electric Properties of TiO2 Films Prepared by Cold Plasma Torch under Atmsopheric Pressure" Mat.Sci.Eng.B. 41. 143-147 (1996)

[Publications] Kazuhiro TAKAHASHI: "Advanced Processing and Characterization of SrTiO3 Single Crystals and Bicrystals for High TC Superconducting Film Substrate" Mat.Sci.Eng.B. 41. 152-156 (1996)

[Publications] Hyun-Kwon HA: "Open Air Plasma Chemical Vapor Deposition of Highly Dielectric Amorphous TiO2 Films" Appl.Phys.Lett.68. 2965-2967 (1996)

[Publications] Mitsutaka MATSUSE: "Atomic Force Microscopy and Sanning Tunneling Microscopy Studies on the Growth Mechanism of a-Si:H Films on Graphite Substrate" J.Non-Crystalline Solids. 200. 787-791 (1996)

[Publications] Tatsuro MAEDA: "Two-dimensional Laser Molecular Beam Epitaxy and Carrier Modulation of Infinite-layer BaCuO2 Films" Physica C. 247. 142-146 (1996)

[Publications] Hideomi KOINUMA: "Pulsed Laser Processing of Carbon and Silicon Clusters and Thin Films" Fullerene Sci.Tech.4. 599-612 (1996)

[Publications] Mitsutaka MATSUSE: "Real-Space Investigation of Initial Growth Process of Hydrogenated Amorphous Silicon on a Graphite Substrate" Phys.Rev.B. 53. 12585-12588 (1996)

[Publications] Myung-Bok LEE: "Pulsed Laser Deposition of Epitaxial Ferroelectric Pb(Zr,Ti)O3 Films on Si(100)Substrate" Jpn.J.Appl.Phys.35. L574-L576 (1996)

[Publications] M.Karppinen: "Determination of Oxygen Contents and Metal Valences in Oxide Superconductors by Chemical Methods" Supercond.Sci.Technol.9. 121-135 (1996)

[Publications] M.Karppinen: "High-pressure Synthesis and Thermal Decomposition of LaCuO_321GC13:Mater.Sci.Engineering B" B41. 59-62 (1996)

[Publications] M.Karppinen: "Synthesis of Various LaCuO_<3-y> Phases by a High-pressure Technique and Subsequent Post-Annealing Treatments" Physica C. 264. 268-274 (1996)

[Publications] M.Karppinen: "Control on the Copper Valence and Properties by Oxygen Content Adjustment in the LaCuO_<3-y> System(0≦y≦0.5)" J.Solid Chem.in the press.

[Publications] M.Karppinen: "Various Themogravimetric Approaches to Oxygen Stoichiometry in Superconducting and Related Cuprates" Proceedings of Themal Analysis Symposium(Univ.of Helsinki,November 1996).in the press.

[Publications] M.Karppinen: "Oxygen Stoichiometry and Copper Valency in Superconducting Cuprates Studied Chemical Methods" Advances in SuperRconductivity IX,Springer-Verlag,Tokyo,1997. in the press.

[Publications] T.Ito: "High-Pressure Synthesis of CuBa_2Ca_<n-1>Cu_nO_x(n=3,4)Superconductors without External Oxidizing Agents" Materials Science & Engineering B. in the press.

[Publications] K.Fujinami: "Ca Doping Effect on Superconductivity in(Yb_<1-x>Ca_x)(Ba_<0.8>Sr_<0.2>)_2Cu_3O_<6+z>" Materials Science & Engineering B. in the press.

[Publications] H.Suematsu: "Simultaneous EDS and EELS Studies on Carbon in CuBa_2Ca_3Cu_4O_x Superconductors" Materials Science & Engineering B. in the press.

[Publications] M.Kawano: "Peak Effect in Stoichiometric SmBa_2Cu_3O_y Samples" Materials Science & Engineering B. in the press.

山内尚雄東京工業大学, 応用セラミックス研究所, 教授 (50271581)