2001 Fiscal Year Annual Research Report

巨大磁気抵抗酸化物における軌道秩序の磁気分光

Research Project

Project/Area Number	12440095
Research Institution	The University of Tokyo
Principal Investigator	十倉好紀東京大学, 大学院・工学系研究科, 教授 (30143382)
Co-Investigator(Kenkyū-buntansha)	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)
Keywords	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
Research Abstract	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。

Research Products
(30 results)

All Other

All Publications (30 results)

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

巨大磁気抵抗酸化物における軌道秩序の磁気分光

Principal Investigator

十倉 好紀 東京大学, 大学院・工学系研究科, 教授 (30143382)

Research Products

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

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

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

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

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

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

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

[Publications] 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)

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

[Publications] 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)

十倉好紀東京大学, 大学院・工学系研究科, 教授 (30143382)