2001 年度実績報告書

巨大磁気抵抗酸化物における軌道秩序の磁気分光

研究課題

研究課題/領域番号	12440095
研究機関	東京大学
研究代表者	十倉好紀東京大学, 大学院・工学系研究科, 教授 (30143382)
研究分担者	田口康二郎東京大学, 大学院・工学系研究科, 助手 (70301132) 木村剛東京大学, 大学院・工学系研究科, 講師 (80323525)
キーワード	巨大磁気抵抗 / 軌道秩序 / 協力的ヤーンテラー変形 / A型反強磁性体 / 電荷移動型絶縁体 / 軌道波 / ラマン散乱
研究概要	今年度は、昨年度に引き続き、軌道秩序を示すペロブスカイト型マンガン酸化物Nd_<1-x>Sr_xMnO_3系のシングルドメインの結晶を作製し、その電子構造の異方性を光反射率スペクトルの測定によって調べた。この系においては、反強磁性絶縁体のNdMnO_3からホールドーピングを行うことによって、ドープ量の増加とともに基底状態は強磁性金属、A型反強磁性金属、C型反強磁性絶縁体と変化する。これらの電気的・磁気的性質は軌道がどのような秩序を示すか、あるいは秩序を持たないかによっていることが知られている。x=0.55のA型反強磁性金属、およびx=0.7のC型反強磁性絶縁体においては、磁気転移を起こすよりも高温側から光学伝導度スペクトルに異方性が認められ、さらに基底状態においては二重交換相互作用により強磁性的に結合した面あるいは鎖に平行方向と垂直方向で大きな異方性が存在することがわかった。これらの結果は軌道秩序が系の電荷ダイナミクスを支配していることを示している。また、基底状態における低エネルギー領域の光学伝導度スペクトルは、強磁性金属においては擬ドゥルーデ的な形状を示すが、A型反強磁性金属においては擬ギャップ的な構造を伴い、またC型反強磁性絶縁体においてはギャップが開いている。これは、軌道秩序およびそれによって生じる磁気秩序の型に依存して、電子系の実効的な次元性が3次元から2次元、1次元と下がっていることによっているものと考えることができる。

研究成果
(30件)

すべてその他

すべて文献書誌 (30件)

[文献書誌] T.Fukumura: "Anisotropic magnetic domain structure of layered manganite La1.4Sr1.6Mn2O7"Appl. Phys. Lett.. 78. 2023-2025 (2001)
[文献書誌] P.Dai: "Jahn-Teller Phonon Anomaly and Dynamic Phase Fluctuations in La0.7Ca0.3MnO3"Phys. Rev. Lett.. 86. 3823-3826 (2001)
[文献書誌] Y.Wakabayashi: "Orbital and Charge Ordering in La1-xSr1+xMnO4(0.4<x<0.5)"J. Phys. Soc. Jpn.. 70. 1194-1197 (2001)
[文献書誌] Y.Lyanda-Geller: "Charge transport in manganites : Hopping conduction, the anomalous Hall effect, and universal scaling"Phys. Rev. B. 63. 184426 (2001)
[文献書誌] F.M.Hess: "Mesoscopic thermodynamics and kineti cs of an inhomogeneous colossal magnetoresistive phase in a bulk crystal"Phys. Rev. B. 63. 180408 (2001)
[文献書誌] M.Ashida: "One-dimensional cuprate as a nonlinear optical material for ultrafast all-optical switching"Appl. Phys. Lett.. 78. 2831-2833 (2001)
[文献書誌] Y.D.Chuang: "Fermi Surface Nesting and Nanoscale Fluctuating Charge/Orbital Ordering in Colossal Magnetoresistive Oxides"Science. 292. 1509-1513 (2001)
[文献書誌] Y.Ogimoto: "Strain-stabilized charge ordering and magnetorelaxor behaviors in Cr-doped Pr0.5Ca0.5MnO3 epitaxial thin films"Appl. Phys. Lett.. 78. 3505-3507 (2001)
[文献書誌] R.Kajimoto: "Commensurate-incommensurate transition in the melting process of orbital ordering in Pr0.5Ca0.5MnO3"Phys. Rev. B. 63. 2124047 (2001)
[文献書誌] M.Fiebig: "Nonlinear Magneto-Optical Properties of Colossal Magnetoresistive"Phys. Rev. Lett.. 86. 6002-6005 (2001)
[文献書誌] M.v Zimmermann: "Resonant x-ray-scattering study of octahedral tilt ordering in LaMnO3 and Pr1-xCaxMnO3"Phys. Rev. B. 64. 064411 (2001)
[文献書誌] M.Izumi: "Insulator-metal transition induced by interlayer coupling in L0.6Sr0.4MnO3/SrTiO3 superlattices"Phys. Rev. B. 64. 064429 (2001)
[文献書誌] K.S.Takahashi: "Interface ferromagnetism in oxide superlattices of CaMnO3/CaRuO3"Appl. Phys. Lett.. 79. 1324-1326 (2001)
[文献書誌] H.Tachibana: "Effect of alkyl chain length on thermochromic phase transition in rethane-substituted polydiacetylene crystals"Polymer. 42. 8311-8314 (2001)
[文献書誌] R.Kajimoto: "Hole concentration dependence of the ordering process of the stripe rder in La2-xSrxNiO4"Phys. Rev. B. 64. 144432 (2001)
[文献書誌] N.P.Armitage: "Nonlinear Magneto-Optical Properties of Colossal Magnetoresistive"Phys. Rev. Lett.. 87. 147003 (2001)
[文献書誌] H.Kishida: "Large Third-Order Optical Nonlinearity of Cu-O Chains Investigated by hird-Harmonic Generation Spectroscopy"Phys. Rev. Lett.. 87. 177401 (2001)
[文献書誌] Y.Okimoto: "Far-Infrared Optical Response of Neutral-Ionic Phase Transition in an rganic Charge-Transfer Complex"Phys. Rev. Lett.. 87. 187401 (2001)
[文献書誌] C.S.Nelson: "Correlated polarons in dissimilar perovskite manganites"Phys. Rev. B. 64. 174405 (2001)
[文献書誌] K.M.Shen: "Surface electronic structure of Sr2RuO4"Phys. Rev. B. 64. 180502 (2001)
[文献書誌] K.Tobe: "Anisotropic optical spectra in a detwinned LaMnO3 crystal"Phys. Rev. B. 64. 184421 (2001)
[文献書誌] M.v.Zimmermann: "X-ray resonant scattering studies of orbital and charge ordering in r1-xCaxMnO3"Phys. Rev. B. 64. 195133 (2001)
[文献書誌] Y.Onose: "Doping Dependence of Pseudogap and Related Charge Dynamics in d2-xCexCuO4"Phys. Rev. Lett.. 87. 217001 (2001)
[文献書誌] T.G.Perring: "Spectacular Doping Dependence of Interlayer Exchange and Other Results on Spin Waves in Bilayer Manganites"Phys. Rev. Lett.. 87. 217201 (2001)
[文献書誌] M.G.Hildebrand: "Far-Infrared Resonance in Sr2RuO4"Phys. Rev. Lett.. 87. 227002 (2001)
[文献書誌] P.Dai: "Magnetic coupling in the insulating and metallic ferromagnetic La1-xCaxMnO3"Phys. Rev. B. 64. 224429 (2001)
[文献書誌] N.Harima: "Chemical potential shift in Nd2-xCexCuO4 : Contrasting behavior between the electron- and hole-doped cuprates"Phys. Rev. B. 64. 2220507 (2001)
[文献書誌] R.Matzdorf: "Surface structural analysis of the layered perovskite Sr2RuO4 by LEED"Phys. Rev. B. 65. 085404 (2002)
[文献書誌] T.Kimura: "Charge-orbital ordering and ferromagnetic chains in single-layered manganite crystals"Phys. Rev. B. 65. 020407 (2002)
[文献書誌] T.Nagai: "Transversely modulated crystal structure of charge-orbital ordered manganites Nd1-xSr1 + xMnO4(x=2/3, 3/4)"Phys. Rev. B. 65. 060405 (2002)

2001 年度 実績報告書

巨大磁気抵抗酸化物における軌道秩序の磁気分光

研究代表者

十倉 好紀 東京大学, 大学院・工学系研究科, 教授 (30143382)

研究成果

[文献書誌] T.Fukumura: "Anisotropic magnetic domain structure of layered manganite La1.4Sr1.6Mn2O7"Appl. Phys. Lett.. 78. 2023-2025 (2001)

[文献書誌] P.Dai: "Jahn-Teller Phonon Anomaly and Dynamic Phase Fluctuations in La0.7Ca0.3MnO3"Phys. Rev. Lett.. 86. 3823-3826 (2001)

[文献書誌] Y.Wakabayashi: "Orbital and Charge Ordering in La1-xSr1+xMnO4(0.4<x<0.5)"J. Phys. Soc. Jpn.. 70. 1194-1197 (2001)

[文献書誌] Y.Lyanda-Geller: "Charge transport in manganites : Hopping conduction, the anomalous Hall effect, and universal scaling"Phys. Rev. B. 63. 184426 (2001)

[文献書誌] F.M.Hess: "Mesoscopic thermodynamics and kineti cs of an inhomogeneous colossal magnetoresistive phase in a bulk crystal"Phys. Rev. B. 63. 180408 (2001)

[文献書誌] M.Ashida: "One-dimensional cuprate as a nonlinear optical material for ultrafast all-optical switching"Appl. Phys. Lett.. 78. 2831-2833 (2001)

[文献書誌] Y.D.Chuang: "Fermi Surface Nesting and Nanoscale Fluctuating Charge/Orbital Ordering in Colossal Magnetoresistive Oxides"Science. 292. 1509-1513 (2001)

[文献書誌] Y.Ogimoto: "Strain-stabilized charge ordering and magnetorelaxor behaviors in Cr-doped Pr0.5Ca0.5MnO3 epitaxial thin films"Appl. Phys. Lett.. 78. 3505-3507 (2001)

[文献書誌] R.Kajimoto: "Commensurate-incommensurate transition in the melting process of orbital ordering in Pr0.5Ca0.5MnO3"Phys. Rev. B. 63. 2124047 (2001)

[文献書誌] M.Fiebig: "Nonlinear Magneto-Optical Properties of Colossal Magnetoresistive"Phys. Rev. Lett.. 86. 6002-6005 (2001)

[文献書誌] M.v Zimmermann: "Resonant x-ray-scattering study of octahedral tilt ordering in LaMnO3 and Pr1-xCaxMnO3"Phys. Rev. B. 64. 064411 (2001)

[文献書誌] M.Izumi: "Insulator-metal transition induced by interlayer coupling in L0.6Sr0.4MnO3/SrTiO3 superlattices"Phys. Rev. B. 64. 064429 (2001)

[文献書誌] K.S.Takahashi: "Interface ferromagnetism in oxide superlattices of CaMnO3/CaRuO3"Appl. Phys. Lett.. 79. 1324-1326 (2001)

[文献書誌] H.Tachibana: "Effect of alkyl chain length on thermochromic phase transition in rethane-substituted polydiacetylene crystals"Polymer. 42. 8311-8314 (2001)

[文献書誌] R.Kajimoto: "Hole concentration dependence of the ordering process of the stripe rder in La2-xSrxNiO4"Phys. Rev. B. 64. 144432 (2001)

[文献書誌] N.P.Armitage: "Nonlinear Magneto-Optical Properties of Colossal Magnetoresistive"Phys. Rev. Lett.. 87. 147003 (2001)

[文献書誌] H.Kishida: "Large Third-Order Optical Nonlinearity of Cu-O Chains Investigated by hird-Harmonic Generation Spectroscopy"Phys. Rev. Lett.. 87. 177401 (2001)

[文献書誌] Y.Okimoto: "Far-Infrared Optical Response of Neutral-Ionic Phase Transition in an rganic Charge-Transfer Complex"Phys. Rev. Lett.. 87. 187401 (2001)

[文献書誌] C.S.Nelson: "Correlated polarons in dissimilar perovskite manganites"Phys. Rev. B. 64. 174405 (2001)

[文献書誌] K.M.Shen: "Surface electronic structure of Sr2RuO4"Phys. Rev. B. 64. 180502 (2001)

[文献書誌] K.Tobe: "Anisotropic optical spectra in a detwinned LaMnO3 crystal"Phys. Rev. B. 64. 184421 (2001)

[文献書誌] M.v.Zimmermann: "X-ray resonant scattering studies of orbital and charge ordering in r1-xCaxMnO3"Phys. Rev. B. 64. 195133 (2001)

[文献書誌] Y.Onose: "Doping Dependence of Pseudogap and Related Charge Dynamics in d2-xCexCuO4"Phys. Rev. Lett.. 87. 217001 (2001)

[文献書誌] T.G.Perring: "Spectacular Doping Dependence of Interlayer Exchange and Other Results on Spin Waves in Bilayer Manganites"Phys. Rev. Lett.. 87. 217201 (2001)

[文献書誌] M.G.Hildebrand: "Far-Infrared Resonance in Sr2RuO4"Phys. Rev. Lett.. 87. 227002 (2001)

[文献書誌] P.Dai: "Magnetic coupling in the insulating and metallic ferromagnetic La1-xCaxMnO3"Phys. Rev. B. 64. 224429 (2001)

[文献書誌] N.Harima: "Chemical potential shift in Nd2-xCexCuO4 : Contrasting behavior between the electron- and hole-doped cuprates"Phys. Rev. B. 64. 2220507 (2001)

[文献書誌] R.Matzdorf: "Surface structural analysis of the layered perovskite Sr2RuO4 by LEED"Phys. Rev. B. 65. 085404 (2002)

[文献書誌] T.Kimura: "Charge-orbital ordering and ferromagnetic chains in single-layered manganite crystals"Phys. Rev. B. 65. 020407 (2002)

[文献書誌] T.Nagai: "Transversely modulated crystal structure of charge-orbital ordered manganites Nd1-xSr1 + xMnO4(x=2/3, 3/4)"Phys. Rev. B. 65. 060405 (2002)

2001 年度実績報告書

十倉好紀東京大学, 大学院・工学系研究科, 教授 (30143382)