2002 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) 本橋輝樹東京工業大学, 応用セラミックス研究所, 助手 (00323840) KARPPINEN Maarit 東京工業大学, 応用セラミックス研究所, 助教授 (50334529)
Keywords	ダブルペロブスカイト / Fe, Co酸化物 / 磁気抵抗(MR)効果 / ハーフメタル / Verwey型相転移 / 混合原子価状態 / メスバウアー分広法
Research Abstract	本研究では、ダブルペロブスカイトにおける新規機能の発現を目指し、Fe, Coを含む3種類のダブルペロブスカイト酸化物において化学組成と電磁気特性の相関関係を調べた。以下に本年度新たに得られた成果を示す。 1.酸素欠損・Aサイトオーダー型(Ba, Sr)REFe_2O_<5+δ>(RE=Nd, Sm, Eu, Dy, Y) (1)幅広いTvの値を持つBaREFe_2O_<5.0>及び(Ba_<1-y>Sr_y)SmFe_2O_<5.0>の試料において、放射光粉末X線回折による結晶構造解析を行った。その結果、RE面を挟むFe-Fe距離がTvの値を支配していることを明らかにした。 (2)RE=Yにおいて、Tv以下でFe^<2+>とFe^<3+>の電荷整列に起因すると思われる超格子反射を観測した。その超格子反射はRE=Tbで報告されているものと構造が異なっており、電荷整列構造がREのイオン半径に関係して変化する可能性を見出した。 2.Bサイトオーダー型A_2Fe(Mo,Re)O_<6-w>(A=Ba,Sr,Ca) (1)Sr_2FeMoO_6において、試料の焼成条件とFe/Moサイト占有秩序度Sの関係を詳細に調べた。その結果、1150℃以下では原子の拡散が、それ以上の温度ではエントロピー効果がそれぞれSの値を支配していることを明らかにし、焼成条件を変えることでS値を幅広く制御可能であることを明らかにした。 (2)A=Ba, Sr, Ca及びその固溶体試料のメスバウアー分光測定を行ったところ、磁性に直接寄与していないAサイトイオンの置換に伴いFeイオンの原子価状態が変化することが分かった。この結果より、同価数元素置換による化学圧力効果が本物質のハーフメタル電子状態に影響を与えることを明らかにした。 3.酸素欠損・Aサイトオーダー型BaRECo_2O_<5+δ>(RE=Nd, Eu, Ho, Y)における結晶構造・磁気特性・MR特性の酸素不定比性依存性を解明し、本物質における巨大MR効果発現のための指針を構築した。 4.以上4年間の研究成果を総括した。本研究により、ダブルペロブスカイトにおける(i)Verwey型相転移など新規機能の創出、及び(ii)ハーフメタルなど機能物質における物性制御法の指針確立、が得られた。

Research Products

(32 results)

All Other

All Publications (32 results)

[Publications] N.Kiryakov, S.Lee, M.Karppinen, H.Yamauchi: "Growth of(Hg, Pb)(Ba, Sr)_2Ca_2Cu_3O_<8+δ> Single Crystals"Superconductor Science and Technology. 15. 54-59 (2002)
[Publications] J.Nakamura, J.Linden, H.Yamauchi, M.Karppinen: "Hole-Doping Effect on the Verwey-Type Transition and Magnetoresistivity of Ba(Sm, Ca)Fe_2O_<5+δ>"Solid State Communications. 121. 269-274 (2002)
[Publications] V.P.S.Awana, S.K.Malik, W.B.Yelon, J.Linden, M.Karppinen, H.Yamauchi: "Intermixing of Fe at Cu(1)-Chain and Cu(2)-Plane Sites in FeSr_2YCu_2O_<7.30> System : A Neutron Diffraction and Mossbauer Spectroscopic Study"Physica B. 312-313. 62-64 (2002)
[Publications] J.Linden, T.Yamamoto, H.Yamauchi, M.Karppinen: "Influence of W/Ta Substitution at the Mo Site on the Fe Valence and Magnetoresistive Properties of Sr_2FeMoO_6"Physica B. 312-313. 787-788 (2002)
[Publications] V.P.S.Awana, S.Ichihara, J.Nakamura, M.Karppinen, H.Yamauchi, J.Yang, W.B.Yelon, W.J.James, S.K.Malik: "Possible Ordering of Ru and Cu in the Charge-Reservoir of Magneto-Superconductor RuSr_2GdCu_2O_8 (Ru-1212) : Magnetic, Transport, and TEM Microstructural Studies"Journal of Applied Physics. 91. 8501-8503 (2002)
[Publications] M.Karppinen, M.Matvejeff, K.Salomaki, H.Yamauchi: "Oxygen Content Analysis of Functional Perovskite-Derived Cobalt Oxides"Journal of Materials Chemistry. 12. 1761-1764 (2002)
[Publications] J.Linden, M.Kochi, K.Lehmus, T.Pietari, M.Karppinen, H.Yamauchi: "Interplay between Cu and Fe Valences in BaR(Cu_<0.5>Fe_<0.5>)_2O_<5+δ> Double Perovskite with R=Lu, Yb, Y, Eu, Sm, Nd and Pr"Journal of Solid State Chemistry. 166. 118-127 (2002)
[Publications] M.Karppinen, H.Yamauchi, T.Nakane, K.Fujinami, K Lehmus, P.Nachimuthu, R.-S.Liu, J.M.Chen: "XANES Study on the Generation and Distribution of Holes with Ca Substitution and O Doping in Cu(Ba_<0.8>Sr_<0.2>)_2(Yb_<1-x>Ca_x)Cu_2O_<6+z>"Journal of Solid State Chemistry. 166. 229-236 (2002)
[Publications] Y.Yasukawa, H.Yamauchi, M.Karppinen: "Accurate Oxygen-Content Determination Method for Decreased Sample Amounts of Superconductive and Other Functional Oxides"Applied Physics Letters. 81. 502-504 (2002)
[Publications] V.P.S.Awana, M.Karppinen, H.Yamauchi: "Comment on Magneto-Superconductivity in Rutheno-Cuprates RuSr_2GdCu_2O_<8-δ> and RuSr_2Gd_<1.5>Ce_<0.5>Cu_2O_<10-δ>"PRAMANA-Journal of Physics. 58. 809-815 (2002)
[Publications] V.P.S.Awana, S.K.Malik, W.B.Yelon, M.Karppinen, H.Yamauchi: "Triple Perovskite CoSr_2YCu_2O_<7-δ> and Its Peculiar Structural Features : A Neutron Diffraction Study"Physica C. 378-381. 155-159 (2002)
[Publications] M.Ushiki, T.Motohashi, H.Yamauchi, M.Karppinen: "High-Pressure Synthesis of the "Zero-Charge-Reservoir" 0223 Superconductor in the Sr-Ca-Cu-O System"Physica C. 378-381. 167-172 (2002)
[Publications] V.P.S.Awana, S.Ichihara, J.Nakamura, M.Karppinen, H.Yamauchi: "Comparison of Magneto-Superconductive Properties of RuSr_2GdCu_2O_<8-δ> and RuSr_2Gd_<1.5>Ce_<0.5>Cu_2O_<10-δ>"Physica C 378-381,249-254(2002). 378-381. 249-254 (2002)
[Publications] Y.Morita, T.Motohashi, S.Sugihara, H.Yamauchi: "High-Quality RE-123 Single Crystals Grown in BaZrO_3 Crucible"Physica C. 378-381. 360-363 (2002)
[Publications] M.Karppinen, N.Kiryakov, Y.Yasukawa, T.Nakane, H.Yamauchi: "Isovalent Cation Substitutions to Control the Intrinsic Hirr Characteristics of Superconductive Copper Oxides"Physica C. 382. 66-71 (2002)
[Publications] V.P.S.Awana, J.Nakamura, M.Karppinen, H.Yamauchi, S.K.Malik: "Glass Component Induced Hysteresis/Memory Effect in Magnetoresistance of Pr_<0.9>Sr_<0.1>CoO_<2.99>"Journal of Magnetism and Magnetic Materials. 250. L6-L11 (2002)
[Publications] M.Karppinen, T.Hosomi, H.Yamauchi: "Redox State Analysis for Understanding the High-Ta Superconductivity in Highly Unstable Ba_2Ca_2Cu_3O_<8-δ> with T_c〜 124 K and Its Derivative Phase with T_c 〜78 K"Physica C. 382. 276-282 (2002)
[Publications] J.Linden, T.Yamamoto, J.Nakamura, H.Yamauchi, M.Karppinen: "Control of Fe valence state and magnetoresisitance by means of T=Ta and W substitution in Sr_2Fe(Mo_<1-x>T_x)O_6"Physical Review B. 66. 184408-184414 (2002)
[Publications] C.A.Cardoso, F.M.Araujo-Moreira, V.P.S.Awana, E.Takayama-Muromachi, O.F.de Lima, H.Yamauchi, M.Karppinen: "Spin Glass Behaviour in RuSr_2Gd_<1.5>Ce_<0.5>Cu_2O_<10-δ>"Physical Review B. 67. 020407(R) (2003)
[Publications] T.Motohashi, R.Ueda, E.Naujalis, T.Tojo, I.Terasaki, T.Atake, M.Karppinen, H.Yamauchi: "Unconventional Magnetic Transition and Transport Behavior in Na_<0.75>CoO_2"Physical Review B. 67. 064406-1-064406-5 (2003)
[Publications] V.P.S.Awana, E.Takayama-Muromachi, S.K.Malik, W.B.Yelon, M.Karppinen, H.Yamauchi, V.V.Krishnamurthy: "Cation Intermixing and Ordering Phenomenon in M-O Layer of MSr_2YCu_2O_z (M-1212)Compounds with M=Fe, Co, Al, and Ga : A Neutron Powder Diffraction Study"Journal of Applied Physics. (in press). (2003)
[Publications] M.Karppinen, K.Kotiranta, T.Nakane, S.C.Chang, J.M.Chen, R.S.Liu, H.Yamauchi: "Layer-Specific Hole Concentrations in Bi_2Sr_2(Y_<1-x>Ca_x)Cu_2O_<8+δ> as Probed by XANES Spectroscopy and Coulometric Redox Analysis"Physical Review B. (in press). (2003)
[Publications] V.P.S.Awana, E.Takayama-Muromachi, M.Karppinen, H.Yamauchi: "Magneto-superconductivity of "100-atm O2-annealed" RuSr_2Gd_<1.5>Ce_<0.5>Cu_2O_<10-δ> (Ru-1222)"Physica C. (in press). (2003)
[Publications] H.Yamauchi, M.Karppinen: "Relationship between Local Atomic Arrangements and Properties of High-T_c Superconductive Copper Oxides"Journal of Low Temperature Physics. (in press). (2003)
[Publications] V.P.S.Awana, M.Karppinen, H.Yamauchi, M.Matvejeff, R.S.Liu, L.-Y.Jang: "Oxygen Content and Valence of Ru in RuSr_2(Gd_<0.75>Ce_<0.25>)_2Cu_2O_<10-δ>"Journal of Low Temperature Physics. (in press). (2003)
[Publications] Y.Morita, M.Karppinen, H.Yamauchi, R.S.Liu, J.M.Chen: "XANES Study on the Evolution among Different Copper Species, Cu^I, Cu^<II> and Cu^<III>, in CuBa_2YCu_2O_<6+z> upon Oxygen Loading"Journal of Low Temperature Physics. (in press). (2003)
[Publications] T.Motohashi, R.Ueda, E.Naujalis, T.Tojo, I.Terasaki, T.Atake, M.Karppinen, H.Yamauchi: "Unconventional Electronic Transition in Na_xCoO_2 with a Precisely Controlled Na Nonstoichiometry"Physica B. (in press). (2003)
[Publications] M.Karppinen, V.P.S.Awana, Y.Morita, H.Yamauchi: "Oxygen Stoichiometry in Co-1212, Co-1222 and Co-1232 of the Homologous Series Co-12s2 of "Category-B" Layered Copper Oxides"Physica C. (in press). (2003)
[Publications] T.Watanabe, N.Kiryakov, J.Poulsen, J.M.Lee, J.M.Chen, R.S.Liu, H.Yamauchi, M.Karppinen: "XANES and wet-chemical analyses of the charge balance in (Hg, Pb)(Ba, Sr)_2Ca_2Cu_3O_<8+δ>"Physica C. (in press). (2003)
[Publications] M.Matvejeff, V.P.S.Awana, L.-Y.Jang, R.S.Liu, H.Yamauchi, M.Karppinen: "Oxygen Non-stoichiometry in Ru-1212 and Ru-1222 Magnetosuperconductors"Physica C. (in press). (2003)
[Publications] T.Motohashi, M.Karppinen, H.Yamauchi: "Electromagnetic and thermoelectric characteristics of Na_xCoO_2 of precisely controlled Na nonstoichiometry"Proceedings of MRS 2002 Fall Meeting (Dec.2-6, Boston, MA, USA). (in press). (2003)
[Publications] T.Motohashi, M.Karppinen, H.Yamauchi: "Oxide Thermoelectrics (Research Signpost, India)"Sodium and oxygen nonstoichiometry and thermoelectric properties of Na_xCoO_<2+δ>. 73-81(9) (2002)

2002 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] N.Kiryakov, S.Lee, M.Karppinen, H.Yamauchi: "Growth of(Hg, Pb)(Ba, Sr)_2Ca_2Cu_3O_<8+δ> Single Crystals"Superconductor Science and Technology. 15. 54-59 (2002)

[Publications] J.Nakamura, J.Linden, H.Yamauchi, M.Karppinen: "Hole-Doping Effect on the Verwey-Type Transition and Magnetoresistivity of Ba(Sm, Ca)Fe_2O_<5+δ>"Solid State Communications. 121. 269-274 (2002)

[Publications] V.P.S.Awana, S.K.Malik, W.B.Yelon, J.Linden, M.Karppinen, H.Yamauchi: "Intermixing of Fe at Cu(1)-Chain and Cu(2)-Plane Sites in FeSr_2YCu_2O_<7.30> System : A Neutron Diffraction and Mossbauer Spectroscopic Study"Physica B. 312-313. 62-64 (2002)

[Publications] J.Linden, T.Yamamoto, H.Yamauchi, M.Karppinen: "Influence of W/Ta Substitution at the Mo Site on the Fe Valence and Magnetoresistive Properties of Sr_2FeMoO_6"Physica B. 312-313. 787-788 (2002)

[Publications] M.Karppinen, M.Matvejeff, K.Salomaki, H.Yamauchi: "Oxygen Content Analysis of Functional Perovskite-Derived Cobalt Oxides"Journal of Materials Chemistry. 12. 1761-1764 (2002)

[Publications] J.Linden, M.Kochi, K.Lehmus, T.Pietari, M.Karppinen, H.Yamauchi: "Interplay between Cu and Fe Valences in BaR(Cu_<0.5>Fe_<0.5>)_2O_<5+δ> Double Perovskite with R=Lu, Yb, Y, Eu, Sm, Nd and Pr"Journal of Solid State Chemistry. 166. 118-127 (2002)

[Publications] Y.Yasukawa, H.Yamauchi, M.Karppinen: "Accurate Oxygen-Content Determination Method for Decreased Sample Amounts of Superconductive and Other Functional Oxides"Applied Physics Letters. 81. 502-504 (2002)

[Publications] V.P.S.Awana, M.Karppinen, H.Yamauchi: "Comment on Magneto-Superconductivity in Rutheno-Cuprates RuSr_2GdCu_2O_<8-δ> and RuSr_2Gd_<1.5>Ce_<0.5>Cu_2O_<10-δ>"PRAMANA-Journal of Physics. 58. 809-815 (2002)

[Publications] V.P.S.Awana, S.K.Malik, W.B.Yelon, M.Karppinen, H.Yamauchi: "Triple Perovskite CoSr_2YCu_2O_<7-δ> and Its Peculiar Structural Features : A Neutron Diffraction Study"Physica C. 378-381. 155-159 (2002)

[Publications] M.Ushiki, T.Motohashi, H.Yamauchi, M.Karppinen: "High-Pressure Synthesis of the "Zero-Charge-Reservoir" 0223 Superconductor in the Sr-Ca-Cu-O System"Physica C. 378-381. 167-172 (2002)

[Publications] V.P.S.Awana, S.Ichihara, J.Nakamura, M.Karppinen, H.Yamauchi: "Comparison of Magneto-Superconductive Properties of RuSr_2GdCu_2O_<8-δ> and RuSr_2Gd_<1.5>Ce_<0.5>Cu_2O_<10-δ>"Physica C 378-381,249-254(2002). 378-381. 249-254 (2002)

[Publications] Y.Morita, T.Motohashi, S.Sugihara, H.Yamauchi: "High-Quality RE-123 Single Crystals Grown in BaZrO_3 Crucible"Physica C. 378-381. 360-363 (2002)

[Publications] M.Karppinen, N.Kiryakov, Y.Yasukawa, T.Nakane, H.Yamauchi: "Isovalent Cation Substitutions to Control the Intrinsic Hirr Characteristics of Superconductive Copper Oxides"Physica C. 382. 66-71 (2002)

[Publications] V.P.S.Awana, J.Nakamura, M.Karppinen, H.Yamauchi, S.K.Malik: "Glass Component Induced Hysteresis/Memory Effect in Magnetoresistance of Pr_<0.9>Sr_<0.1>CoO_<2.99>"Journal of Magnetism and Magnetic Materials. 250. L6-L11 (2002)

[Publications] M.Karppinen, T.Hosomi, H.Yamauchi: "Redox State Analysis for Understanding the High-Ta Superconductivity in Highly Unstable Ba_2Ca_2Cu_3O_<8-δ> with T_c〜 124 K and Its Derivative Phase with T_c 〜78 K"Physica C. 382. 276-282 (2002)

[Publications] J.Linden, T.Yamamoto, J.Nakamura, H.Yamauchi, M.Karppinen: "Control of Fe valence state and magnetoresisitance by means of T=Ta and W substitution in Sr_2Fe(Mo_<1-x>T_x)O_6"Physical Review B. 66. 184408-184414 (2002)

[Publications] C.A.Cardoso, F.M.Araujo-Moreira, V.P.S.Awana, E.Takayama-Muromachi, O.F.de Lima, H.Yamauchi, M.Karppinen: "Spin Glass Behaviour in RuSr_2Gd_<1.5>Ce_<0.5>Cu_2O_<10-δ>"Physical Review B. 67. 020407(R) (2003)

[Publications] T.Motohashi, R.Ueda, E.Naujalis, T.Tojo, I.Terasaki, T.Atake, M.Karppinen, H.Yamauchi: "Unconventional Magnetic Transition and Transport Behavior in Na_<0.75>CoO_2"Physical Review B. 67. 064406-1-064406-5 (2003)

[Publications] M.Karppinen, K.Kotiranta, T.Nakane, S.C.Chang, J.M.Chen, R.S.Liu, H.Yamauchi: "Layer-Specific Hole Concentrations in Bi_2Sr_2(Y_<1-x>Ca_x)Cu_2O_<8+δ> as Probed by XANES Spectroscopy and Coulometric Redox Analysis"Physical Review B. (in press). (2003)

[Publications] V.P.S.Awana, E.Takayama-Muromachi, M.Karppinen, H.Yamauchi: "Magneto-superconductivity of "100-atm O2-annealed" RuSr_2Gd_<1.5>Ce_<0.5>Cu_2O_<10-δ> (Ru-1222)"Physica C. (in press). (2003)

[Publications] H.Yamauchi, M.Karppinen: "Relationship between Local Atomic Arrangements and Properties of High-T_c Superconductive Copper Oxides"Journal of Low Temperature Physics. (in press). (2003)

[Publications] V.P.S.Awana, M.Karppinen, H.Yamauchi, M.Matvejeff, R.S.Liu, L.-Y.Jang: "Oxygen Content and Valence of Ru in RuSr_2(Gd_<0.75>Ce_<0.25>)_2Cu_2O_<10-δ>"Journal of Low Temperature Physics. (in press). (2003)

[Publications] Y.Morita, M.Karppinen, H.Yamauchi, R.S.Liu, J.M.Chen: "XANES Study on the Evolution among Different Copper Species, Cu^I, Cu^<II> and Cu^<III>, in CuBa_2YCu_2O_<6+z> upon Oxygen Loading"Journal of Low Temperature Physics. (in press). (2003)

[Publications] T.Motohashi, R.Ueda, E.Naujalis, T.Tojo, I.Terasaki, T.Atake, M.Karppinen, H.Yamauchi: "Unconventional Electronic Transition in Na_xCoO_2 with a Precisely Controlled Na Nonstoichiometry"Physica B. (in press). (2003)

[Publications] M.Karppinen, V.P.S.Awana, Y.Morita, H.Yamauchi: "Oxygen Stoichiometry in Co-1212, Co-1222 and Co-1232 of the Homologous Series Co-12s2 of "Category-B" Layered Copper Oxides"Physica C. (in press). (2003)

[Publications] T.Watanabe, N.Kiryakov, J.Poulsen, J.M.Lee, J.M.Chen, R.S.Liu, H.Yamauchi, M.Karppinen: "XANES and wet-chemical analyses of the charge balance in (Hg, Pb)(Ba, Sr)_2Ca_2Cu_3O_<8+δ>"Physica C. (in press). (2003)

[Publications] M.Matvejeff, V.P.S.Awana, L.-Y.Jang, R.S.Liu, H.Yamauchi, M.Karppinen: "Oxygen Non-stoichiometry in Ru-1212 and Ru-1222 Magnetosuperconductors"Physica C. (in press). (2003)

[Publications] T.Motohashi, M.Karppinen, H.Yamauchi: "Electromagnetic and thermoelectric characteristics of Na_xCoO_2 of precisely controlled Na nonstoichiometry"Proceedings of MRS 2002 Fall Meeting (Dec.2-6, Boston, MA, USA). (in press). (2003)

[Publications] T.Motohashi, M.Karppinen, H.Yamauchi: "Oxide Thermoelectrics (Research Signpost, India)"Sodium and oxygen nonstoichiometry and thermoelectric properties of Na_xCoO_<2+δ>. 73-81(9) (2002)

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