2000 Fiscal Year Annual Research Report

ダブル・ペロブスカイトにおける新規機能の創出

Research Project

Project/Area Number	11305002
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)	谷山智康東京工業大学, 大学院・総合理工学研究科, 助手 (10302960) 末松久幸長岡技術科学大学, 極限エネルギー密度工学研究センター, 助教授 (30222045) 山崎陽太郎東京工業大学, 大学院・総合理工学研究科, 教授 (50124706)
Keywords	ダブルペロブスカイト / 磁気抵抗(MR)効果 / Verwey型総転移 / 混合原子価状態 / 酸素ゲッター / メスバウアー分光法
Research Abstract	本研究では、ダブルペロブスカイト型構造を持つ遷移金属酸化物において"新しい機能"を創出することを目指し、2種類のダブルペロブスカイト型Fe酸化物の電磁気特性に関する研究を行った。具体的には元素置換・酸素量制御など化学的手法を駆使した高品質試料の合成、及び得られた物質における電磁気特性の評価である。特に本研究では、メスバウアー分光法を用いてFeイオンの磁性状態を詳細に調べた点が特徴となっている。以下に主な成果を示す。 1.Aサイトオーダー酸素欠損ダブルペロブスカイト:BaSm(Fe,CU)_2O_<5+w> (1)我々が数年来研究してきたBaSm(Fe_<0.5-x>Cu_<0.5+x>)2O_<5+w>について、更に広い組成領域(-0.5【less than or equal】x【less than or equal】-0.4,-0.1【less than or equal】x【less than or equal】0.0)での合成法の確立:試料を酸素ゲッター(金属Fe)とともに石英管中で焼成することにより、これまで得ることができなかったBaSmFe_2O_<5+w>(x=-0.5)の合成に成功。 (2)^<57>Feメスバウアー分光法を用いたBaSm(Fe_<0.5-x>Cu_<0.5+x>)2O_<5+w>(-0.5【less than or equal】x【less than or equal】-0.4)におけるFeイオンの特異な原子価状態の発見:本物質ではFeイオンが混合原子価状態(Fe^<2.5+>)にあり、また200K付近に電荷分離(Verwey型)相転移を持つことを確認。 (3)BaSmFe_2O_<5+w>における負のMR効果の発見、及びMR効果とVerwey型相転移の相関関係を確立。 (4)BaSmFe_2O_<5+w>のMR効果に対する酸素量w及びSm→Ca置換効果の影響に関する知見の獲得。 2.Bサイトオーダーダブルペロブスカイト:Sr_2FeMoO_<6-w> (1)金属Feを酸素ゲッターとして用いた真空封じ切り法による合成法の確立。 (2)Sr_2FeMoO_<6-w>において、全ての温度領域(5-300K)でFeイオンが混合原子価状態(Fe^<2.5+>)にあることを^<57>Feメスバウアー分光法により確認。 (3)Sr_2Fe(Mo,W)O_<6-w>における酸素量の決定:化学滴定法を用いて本物質の酸素欠損wがほぼ0であることを実験的に確認。 (4)Sr_2Fe(Mo,W)O_<6-w>系において、粒内MRと粒間トンネル型MRが共存する可能性を示唆。 (5)Sr_2FeMoO_<6-w>のMoサイトをTaに置換することにより、本系最大の207%のMR効果を発見。

Research Products
(38 results)

All Other

All Publications (38 results)

[Publications] J.Linden,J.Nakamura,P.Karen,A.Kjekshus,M.Karppinen,and H.Yamauchi: "Observation of mixed-valence state in the BaSm(Cu_<1-x>Fe_x)_2O_<5+δ> double-perovskite phase"Advances in Superconductivity. XII. 95-97 (2000)
[Publications] K.Lehmus,M.Kochi,M.Karppinen,H.Yamauchi,and L.Niinisto: "Variation of oxygen stoichiometry in BaRE(Cu_<1-x>Fe_x)_2O_<5+δ> double perovskite upon heat treatments under ambient and high pressure"Int.J.Inorg.Mater.. 2. 203-208 (2000)
[Publications] J.Linden,T.Yamamoto,M.Karppinen,H.Yamauchi,T.Pietari: "Evidence for valence fluctuation of Fe in Sr_2FeMoO_<6-w> double perovskite"Appl.Phys.Lett.. 76. 2925-2927 (2000)
[Publications] J.Nakamura,J.Linden,H.Suematsu,M.Karppinen,and H.Yamauchi: "Iron mixed valence compounds, BaSm(Cu_<0.5+x>Fe_<0.5-x>)_2O_<5+δ> I : Synthesis and chemical characterization"Physica C. 338. 121-125 (2000)
[Publications] J.Linden,J.Nakamura,T.Pietari,T.Taniyama,M.Karppinen,and H.Yamauchi: "Iron mixed valence compounds, BaSm(Cu_<0.5+x>Fe_<0.5-x>)_2O_<5+δ> II : The Fe2.5+ state and magnetic properties"Physica C. 338. 126-131 (2000)
[Publications] M.Kochi,J.Linden,T.Taniyama,K.Lehmus,M.Karppinen,and H.Yamauchi: "Magnetic properties,oxygen content and metal valences in BaRE(Cu_<0.5>Fe_<0.5>)_2O_<5+δ> with RE=Lu, Yb, Y, Eu, Nd, and Pr"Physica C. 338. 132-136 (2000)
[Publications] T.Yamamoto,J.Liimatainen,J.Linden,M.Karppinen,and H.Yamauchi: "Novel methods of synthesis and wet-chemical redox analysis for magnetoresistive double-perovskite Sr_2FeMoO_<6-w>"J.Mater.Chem.. 10(10). 2342-2345 (2000)
[Publications] J.Nakamura,J.Linden,M.Karppinen,and H.Yamauchi: "Magnetoresistance effect in the fluctuating-valence BaSmFe_2O_<5+δ> system"Appl.Phys.Lett.. 77(11). 1683-1685 (2000)
[Publications] H.Yamauchi,M.Karppinen,and J.Linden: "Chemical control of metal valences and magnetic properties in various A-or B-site ordered iron-oxide double perovskite"Proceedings of 8^<th> International Conference on Ferrites. (in press).
[Publications] V.P.S.Awana,J.Nakamura,M.Karppinen,H.Yamauchi,S.K.Malik,and W.B.Yelon: "Synthesis and magnetism of Pr-based rutheno-cuprate compound RuSr_2PrCu_2O_<8-δ>"Physica C. (in press).
[Publications] J.Linden,T.Yamamoto,J.Nakamura,M.Karppinen,and H.Yamauchi: "Co-existence of intrinsic and extrinsic magnetoresistance in the double-perovskite Sr_2Fe(Mo_<1-x>W_x)O_<6-w> system"Appl.Phys.Lett.. (in press).
[Publications] V.P.S.Awana,M.Karppinen,H.Yamauchi et al.: "Magnetization and heat capacity of R_<1/3>Sr_<2/3>FeO_<3-δ>(R=La and Pr)"IEEE Tans.Magnet.. (in press).
[Publications] H.Suematsu,T.Ito,T.Katsura,M.Karppinen,and H.Yamauchi: "Peak effect in critical current density induced by oxygen deficiency in the CuBa_2Ca_3Cu_4O_<10+δ> superconductor"Supercond.Sci.Technol.. 13. 930-934 (2000)
[Publications] T.Akao,S.Lee,H.Suematsu,K.Kurashima,and H.Yamauchi: "Hecto-Angstrom modulation and peak effect in superconducting (Hg,Pb)(Ba,Sr)-1223"Physica C. 338. 298-304 (2000)
[Publications] H.Yamauchi and M.Karppinen: "Impact of the "Zero" homologous series,01(n-1)n and 02(n-1)n"Physica C. 335. 273-278 (2000)
[Publications] H.Yamauchi and M.Karppinen: "Application of high-pressure techniques : stabilization and oxidation-state control of novel superconductive and related multi-layered copper oxides"Supercond.Sci.Technol.. 13. R33-R52 (2000)
[Publications] H.Suematsu,T.Akao,S.Lee,S.Nagaya,K.Kurashima,Y.Bando,and H.Yamauchi: "The "Stage" for the vortices to play peak effect in the J_c properties of high-T_c superconductors : a novel TEM approach"Proceedings of the 7^<th> NIRIM International Symposium on Advanced Materials. (in press).
[Publications] M.Karppinen,H.Yamauchi,T.Nakane,and M.Kotiranta: "Oxygen non-stoichiometry and hole distribution in multi-layered copper oxides : understanding of the magnetic-irreversibility characteristics"Physica C. 338. 18-24 (2000)
[Publications] T.Nakane,Y.Yasukawa,E.S.Otabe,T.Matsushita,M.Karppinen,and H.Yamauchi: "Effects of Sr substitution on the magnetic-field irreversibility in superconductive Cu(Ba_<1-y>Sr_y)_2YbCu_2O_<6+z>"Physica C. 338. 25-28 (2000)
[Publications] H.Yamauchi,M.Karppinen,T.Hosomi,and H.Fjellvag: "Water-containing phases derived from "02(n-1)n" superconductors.I : Novel 02(n-1)n homologous series in the Ba-Ca-Cu-O system and the derivative series"Physica C. 338. 38-45 (2000)
[Publications] H.Yamauchi,M.Karppinen,T.Hosomi,and H.Suematsu: "Water-containing phases derived from "02(n-1)n" superconductors. II :Derivative of the Sr_2Ca_2Cu_3O_<8+δ>(0^<(Sr)>223)phase"Physica C. 338. 46-51 (2000)
[Publications] H.Suematsu,H.Okamura,S.Lee,S.Nagaya,and H.Yamauchi: "Y-Ba-Cu-O melt-growth bulks : modulation in oxygen distribution"Physica C. 338. 96-102 (2000)
[Publications] Y.Takahama,H.Suematsu,T.Matsushita,and H.Yamauchi: "Dependence of peak effect on particle size distribution in superconducting SmBa_2Cu_3O_<7-δ> powder sample"Physica C. 338. 115-120 (2000)
[Publications] T.Akao,S.Lee,K.Mizogami,H.Suematsu,and H.Yamauchi: "Irreversibility-field enhancement by optimizing hole density distribution in the Hg-1212 superconductor"Physica C. 338. 76-83 (2000)
[Publications] S.Lee,T.Akao,N.Kiryakov,H.Suematsu,and H.Yamauchi: "Development of Hg-containing superconductors : form precursors to materials prototypes"Physica C. 338. 60-66 (2000)
[Publications] K.Yamawaki,S.Sasaki,S.Lee,T.Akao,and H.Yamauchi: "Single-crystal x-ray study of (Hg,Pb)-1223 superconductor at low temperature"Physica C. 338. 67-71 (2000)
[Publications] M.Karppinen and H.Yamauchi: "Hole-deping routes for understanding the relationship between atomic arrangements and superconductivity properties in multi-layered copper oxides"J.Inorg.Mater.. 2(6). 589-599 (2000)
[Publications] T.Nakane,M.Karppinen,and H.Yamauchi: "Synthesis of superconductive Cu_2Ba_2 (Y,Ca) Cu_2O_<8±δ> phase by novel encapsulation technique"Supercond.Sci.Tech.. 13(7). 1382-1386 (2000)
[Publications] T.Nakane,M.Karppinen and H.Yamauchi: "Magnetic-field irreversibility in superconductive Cu-2212 phase with double-Cu_2O_2-chane charge reservoir"Supercond.Sci.Tech.. 13. 1436-1440 (2000)
[Publications] M.Karppinen,M.Kotiranta,H.Yamauchi,P.Nachimuthu,R.S.Liu,and J.M.Chen: "O K-edge and Cu L_<23>-edge XANES study on the concentration and distribution of holes in the (Pb_<2/3>Cu_<1/3>)_3Sr_2(Y,Ca)Cu_2O_<8±z> superconductive phase"Phys.Rev.B. (in press).
[Publications] H.Suematsu,K.Udo,K.Hisatsune,K.Yatsui,and H.Yamauchi: "Novel large-area high-resolution-transmission-electron-microscopy technique using specimens fabricated by a focused ion beam"Jpn.J.Appl.Phys.. (in press).
[Publications] Y.Yasukawa,T.Nakane,M.Karppinen,and H.Yamauchi: "Consequence of isovalent RE substitution to magnetic irreversibility in cation-stoichiometric CuBa_2RECu_2O_<6.93±0.01>"Appl.Phys.Lett.. (in press).
[Publications] Y.Yasukawa,T.Nakane,M.Karppinen,and H.Yamauchi: "Rare-earth-ion-size control on magnetic irreversibility field in CuBa_2RECu_2O_<7-δ>"Physica C. (in press).
[Publications] N.Kiryakov,S.Lee,M.Karppinen,and H.Yamauchi: "Single crystals of (Hg,Pb) (Ba,Sr)_2Ca_2Cu_3O_<8+δ> grown by an improved encapsulation technique"Physica C. (in press).
[Publications] T.Nakane,M.Karppinen,and H.Yamauchi: "Magnetic-field irreversibility in supereonductive Cu-m212(m=1,2)"Physica C. (in press).
[Publications] N.Kiryakov,S.Lee,M.Karppinen,and H.Yamauchi: "Growth of (Hg,Pb)(Ba,Sr)_2Ca_2Cu_3O_<8+δ> single crystals"J.Mater.Chem.. (in press).
[Publications] K.Yamawaki,S.Sasaki,M.Tanaka,H.Yamauchi,and S.Lee: "Cation distribution in Hg site of (Hg,Pb)-1223 determined by synchrotron x-ray anomalous scattering"Physica C. (in press).
[Publications] H.Yamauchi and M.Karppinen: "Proceedings of the International Discussion Meeting on Chemistry Approaches to High-T_c Supperconductive Materials/Chem-HTSC-V (Yokohama,October 15-16,1999)"North-Holland. 167 (2000)

2000 Fiscal Year Annual Research Report

ダブル・ペロブスカイトにおける新規機能の創出

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] J.Linden,J.Nakamura,P.Karen,A.Kjekshus,M.Karppinen,and H.Yamauchi: "Observation of mixed-valence state in the BaSm(Cu_<1-x>Fe_x)_2O_<5+δ> double-perovskite phase"Advances in Superconductivity. XII. 95-97 (2000)

[Publications] K.Lehmus,M.Kochi,M.Karppinen,H.Yamauchi,and L.Niinisto: "Variation of oxygen stoichiometry in BaRE(Cu_<1-x>Fe_x)_2O_<5+δ> double perovskite upon heat treatments under ambient and high pressure"Int.J.Inorg.Mater.. 2. 203-208 (2000)

[Publications] J.Linden,T.Yamamoto,M.Karppinen,H.Yamauchi,T.Pietari: "Evidence for valence fluctuation of Fe in Sr_2FeMoO_<6-w> double perovskite"Appl.Phys.Lett.. 76. 2925-2927 (2000)

[Publications] J.Nakamura,J.Linden,H.Suematsu,M.Karppinen,and H.Yamauchi: "Iron mixed valence compounds, BaSm(Cu_<0.5+x>Fe_<0.5-x>)_2O_<5+δ> I : Synthesis and chemical characterization"Physica C. 338. 121-125 (2000)

[Publications] J.Linden,J.Nakamura,T.Pietari,T.Taniyama,M.Karppinen,and H.Yamauchi: "Iron mixed valence compounds, BaSm(Cu_<0.5+x>Fe_<0.5-x>)_2O_<5+δ> II : The Fe2.5+ state and magnetic properties"Physica C. 338. 126-131 (2000)

[Publications] M.Kochi,J.Linden,T.Taniyama,K.Lehmus,M.Karppinen,and H.Yamauchi: "Magnetic properties,oxygen content and metal valences in BaRE(Cu_<0.5>Fe_<0.5>)_2O_<5+δ> with RE=Lu, Yb, Y, Eu, Nd, and Pr"Physica C. 338. 132-136 (2000)

[Publications] T.Yamamoto,J.Liimatainen,J.Linden,M.Karppinen,and H.Yamauchi: "Novel methods of synthesis and wet-chemical redox analysis for magnetoresistive double-perovskite Sr_2FeMoO_<6-w>"J.Mater.Chem.. 10(10). 2342-2345 (2000)

[Publications] J.Nakamura,J.Linden,M.Karppinen,and H.Yamauchi: "Magnetoresistance effect in the fluctuating-valence BaSmFe_2O_<5+δ> system"Appl.Phys.Lett.. 77(11). 1683-1685 (2000)

[Publications] H.Yamauchi,M.Karppinen,and J.Linden: "Chemical control of metal valences and magnetic properties in various A-or B-site ordered iron-oxide double perovskite"Proceedings of 8^<th> International Conference on Ferrites. (in press).

[Publications] V.P.S.Awana,J.Nakamura,M.Karppinen,H.Yamauchi,S.K.Malik,and W.B.Yelon: "Synthesis and magnetism of Pr-based rutheno-cuprate compound RuSr_2PrCu_2O_<8-δ>"Physica C. (in press).

[Publications] J.Linden,T.Yamamoto,J.Nakamura,M.Karppinen,and H.Yamauchi: "Co-existence of intrinsic and extrinsic magnetoresistance in the double-perovskite Sr_2Fe(Mo_<1-x>W_x)O_<6-w> system"Appl.Phys.Lett.. (in press).

[Publications] V.P.S.Awana,M.Karppinen,H.Yamauchi et al.: "Magnetization and heat capacity of R_<1/3>Sr_<2/3>FeO_<3-δ>(R=La and Pr)"IEEE Tans.Magnet.. (in press).

[Publications] H.Suematsu,T.Ito,T.Katsura,M.Karppinen,and H.Yamauchi: "Peak effect in critical current density induced by oxygen deficiency in the CuBa_2Ca_3Cu_4O_<10+δ> superconductor"Supercond.Sci.Technol.. 13. 930-934 (2000)

[Publications] T.Akao,S.Lee,H.Suematsu,K.Kurashima,and H.Yamauchi: "Hecto-Angstrom modulation and peak effect in superconducting (Hg,Pb)(Ba,Sr)-1223"Physica C. 338. 298-304 (2000)

[Publications] H.Yamauchi and M.Karppinen: "Impact of the "Zero" homologous series,01(n-1)n and 02(n-1)n"Physica C. 335. 273-278 (2000)

[Publications] H.Yamauchi and M.Karppinen: "Application of high-pressure techniques : stabilization and oxidation-state control of novel superconductive and related multi-layered copper oxides"Supercond.Sci.Technol.. 13. R33-R52 (2000)

[Publications] H.Suematsu,T.Akao,S.Lee,S.Nagaya,K.Kurashima,Y.Bando,and H.Yamauchi: "The "Stage" for the vortices to play peak effect in the J_c properties of high-T_c superconductors : a novel TEM approach"Proceedings of the 7^<th> NIRIM International Symposium on Advanced Materials. (in press).

[Publications] M.Karppinen,H.Yamauchi,T.Nakane,and M.Kotiranta: "Oxygen non-stoichiometry and hole distribution in multi-layered copper oxides : understanding of the magnetic-irreversibility characteristics"Physica C. 338. 18-24 (2000)

[Publications] T.Nakane,Y.Yasukawa,E.S.Otabe,T.Matsushita,M.Karppinen,and H.Yamauchi: "Effects of Sr substitution on the magnetic-field irreversibility in superconductive Cu(Ba_<1-y>Sr_y)_2YbCu_2O_<6+z>"Physica C. 338. 25-28 (2000)

[Publications] H.Yamauchi,M.Karppinen,T.Hosomi,and H.Fjellvag: "Water-containing phases derived from "02(n-1)n" superconductors.I : Novel 02(n-1)n homologous series in the Ba-Ca-Cu-O system and the derivative series"Physica C. 338. 38-45 (2000)

[Publications] H.Yamauchi,M.Karppinen,T.Hosomi,and H.Suematsu: "Water-containing phases derived from "02(n-1)n" superconductors. II :Derivative of the Sr_2Ca_2Cu_3O_<8+δ>(0^<(Sr)>223)phase"Physica C. 338. 46-51 (2000)

[Publications] H.Suematsu,H.Okamura,S.Lee,S.Nagaya,and H.Yamauchi: "Y-Ba-Cu-O melt-growth bulks : modulation in oxygen distribution"Physica C. 338. 96-102 (2000)

[Publications] Y.Takahama,H.Suematsu,T.Matsushita,and H.Yamauchi: "Dependence of peak effect on particle size distribution in superconducting SmBa_2Cu_3O_<7-δ> powder sample"Physica C. 338. 115-120 (2000)

[Publications] T.Akao,S.Lee,K.Mizogami,H.Suematsu,and H.Yamauchi: "Irreversibility-field enhancement by optimizing hole density distribution in the Hg-1212 superconductor"Physica C. 338. 76-83 (2000)

[Publications] S.Lee,T.Akao,N.Kiryakov,H.Suematsu,and H.Yamauchi: "Development of Hg-containing superconductors : form precursors to materials prototypes"Physica C. 338. 60-66 (2000)

[Publications] K.Yamawaki,S.Sasaki,S.Lee,T.Akao,and H.Yamauchi: "Single-crystal x-ray study of (Hg,Pb)-1223 superconductor at low temperature"Physica C. 338. 67-71 (2000)

[Publications] M.Karppinen and H.Yamauchi: "Hole-deping routes for understanding the relationship between atomic arrangements and superconductivity properties in multi-layered copper oxides"J.Inorg.Mater.. 2(6). 589-599 (2000)

[Publications] T.Nakane,M.Karppinen,and H.Yamauchi: "Synthesis of superconductive Cu_2Ba_2 (Y,Ca) Cu_2O_<8±δ> phase by novel encapsulation technique"Supercond.Sci.Tech.. 13(7). 1382-1386 (2000)

[Publications] T.Nakane,M.Karppinen and H.Yamauchi: "Magnetic-field irreversibility in superconductive Cu-2212 phase with double-Cu_2O_2-chane charge reservoir"Supercond.Sci.Tech.. 13. 1436-1440 (2000)

[Publications] M.Karppinen,M.Kotiranta,H.Yamauchi,P.Nachimuthu,R.S.Liu,and J.M.Chen: "O K-edge and Cu L_<23>-edge XANES study on the concentration and distribution of holes in the (Pb_<2/3>Cu_<1/3>)_3Sr_2(Y,Ca)Cu_2O_<8±z> superconductive phase"Phys.Rev.B. (in press).

[Publications] H.Suematsu,K.Udo,K.Hisatsune,K.Yatsui,and H.Yamauchi: "Novel large-area high-resolution-transmission-electron-microscopy technique using specimens fabricated by a focused ion beam"Jpn.J.Appl.Phys.. (in press).

[Publications] Y.Yasukawa,T.Nakane,M.Karppinen,and H.Yamauchi: "Consequence of isovalent RE substitution to magnetic irreversibility in cation-stoichiometric CuBa_2RECu_2O_<6.93±0.01>"Appl.Phys.Lett.. (in press).

[Publications] Y.Yasukawa,T.Nakane,M.Karppinen,and H.Yamauchi: "Rare-earth-ion-size control on magnetic irreversibility field in CuBa_2RECu_2O_<7-δ>"Physica C. (in press).

[Publications] N.Kiryakov,S.Lee,M.Karppinen,and H.Yamauchi: "Single crystals of (Hg,Pb) (Ba,Sr)_2Ca_2Cu_3O_<8+δ> grown by an improved encapsulation technique"Physica C. (in press).

[Publications] T.Nakane,M.Karppinen,and H.Yamauchi: "Magnetic-field irreversibility in supereonductive Cu-m212(m=1,2)"Physica C. (in press).

[Publications] N.Kiryakov,S.Lee,M.Karppinen,and H.Yamauchi: "Growth of (Hg,Pb)(Ba,Sr)_2Ca_2Cu_3O_<8+δ> single crystals"J.Mater.Chem.. (in press).

[Publications] K.Yamawaki,S.Sasaki,M.Tanaka,H.Yamauchi,and S.Lee: "Cation distribution in Hg site of (Hg,Pb)-1223 determined by synchrotron x-ray anomalous scattering"Physica C. (in press).

[Publications] H.Yamauchi and M.Karppinen: "Proceedings of the International Discussion Meeting on Chemistry Approaches to High-T_c Supperconductive Materials/Chem-HTSC-V (Yokohama,October 15-16,1999)"North-Holland. 167 (2000)

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