2000 年度実績報告書

軌道相転移の制御による新物質創製

研究課題

研究課題/領域番号	11220207
研究機関	青山学院大学
研究代表者	秋光純青山学院大学, 理工学部, 教授 (80013522)
研究分担者	廣田和馬東北大学, 大学院・理学研究科, 助教授 (90272012) 有馬孝尚筑波大学, 物質工学系, 助教授 (90232066) 古川信夫青山学院大学, 理工学部, 助教授 (00238669)
キーワード	軌道整列 / マンガン系酸化物 / 四重極秩序 / ペロブスカイト
研究概要	主に軌道整列の直接観測について、総合的に研究した。それを要約すると以下のようになる。 1)軌道がフラストレートしていると考えられているLu_2V_2O_7について、中性子回折を用いてその軌道秩序を観測した。この結果、軌道が四面体の111方向に向かっている新しい軌道整列であることが判明した。 2)Lu_2V_2O_7における軌道整列を理論的に研究した。この物質の強磁性の起源として軌道整列によるKugel-Khomskii相互作用が考えられている。本研究では、パイロクロア格子上のVの3d電子を3重縮重系ととらえ、同一サイト内でのクーロン相互作用を最小化する軌道配列を考察した。その結果、フラストレーションを解消する軌道カイラル状態が安定であることが示唆された。 3)磁化反転現象を示すYVO3の軌道逐次相転移を共鳴X線散乱実験によって確認した。軌道秩序が反強磁性より高い温度から始まることが示唆される。 4)金属絶縁体転移と奇妙な磁性を示す二重ペロブスカイト型コバルト酸化物について中性子散乱を行った。金属絶縁体転移は中間スピン状態にある三価のコバルトイオンのモット転移とみなせる。また、その転移温度直下の強磁性や反強磁性はスピンキャンティングが〉原因であると考えられることがわかった。 5)四重極秩序があると考えられているCeB_6についてその軌道を観測することを試みた。得られた結果は大変予想外であり、最近接のBとBの間、および三角形のBの中にスピンがほぼ一様に分布しているという結果が得られた。 6)HoB_2C_2の反強四極子秩序転移が反強磁性転移と同じ温度T_Qで起こることを、共鳴X線散乱実験によって確認した。この結果はT_Q以上に反強磁性秩序相が存在するとした従来の粉末中性子回折実験の結果と矛盾するため、単結晶を用いた中性子回折実験を行った。T_Q以上では格子非整合な位置にブロードな磁気散乱(サテライトピーク)が出現し、さらに、サテライトに囲まれた領域に散漫散乱が存在することを見いだした。このことは低温相とは異なる周期構造をもつ短距離磁気相関があることを示している。

研究成果
(38件)

すべてその他

すべて文献書誌 (38件)

[文献書誌] H.Ichikawa et.al.: "Direct Observation of Orbital Ordering in YTiO_3"Physica.B. 281-282. 482-484 (2000)
[文献書誌] S.Ohsugi. et. al.: "Cu NMR and NQR studies on the magnetic order in Sr_<2.5>Ca_<11.5>Cu_<2441>"Physica.B. 284-288. 1591-1592 (2000)
[文献書誌] Y.Gotoh et. al.: "Role of structural modulation in the composite crystal (Sr_2Cu_2O_3)_<0.70>CuO_2, "Sr_<14>Cu_<24>O_<41>" with two-legged spin ladder"Physica C. 341-348. 469-470 (2000)
[文献書誌] T.Nakanishi et. al.: "Upper Critical Field of Spin-Ladder Sr_2Ca_<12>Cu_<24>O_<41>"Physica.B. 281-282. 957-958 (2000)
[文献書誌] D.Braithwaite et. al.: "Upper Critical Field of the Spin Ladder System Sr_<2.5>Ca_<11.5>O_<41>"Solid State Commun.. 114. 533-536 (2000)
[文献書誌] M.Hiroi et.al.: "Study on CuGe_<0.9885>Si_<0.0115>O_3 in High Magnetic Fields by Specific Heat Measurements"Physica B. 281 and 282. 669-670 (2000)
[文献書誌] A.Zheludev et.al.: "Role of Single Ion Excitations in the Mixed-Spin Quasi-One-Dimensional Quantum Antiferromagnet Nd_2BaNiO_5"Phys.Rev.B. Vol.61. 11601-11612 (2000)
[文献書誌] T.Yokoo et.al.: "Magnetic Excitations in the Haldane System R_2BaNiO_5"J.Phys.Soc.Jpn.. 69Suppl.B. 95-101 (2000)
[文献書誌] 永田貴志 et.al.: "梯子格子系超伝導体;(Sr,Ca)_<14>Cu_<24>O_<41>の物性"物性研究. Vol.74 No.4. 357-368 (2000)
[文献書誌] J.Kikuchi et.al: "NMR and Newtron Scattering Studies of Quasi One-Dimensional Magnet CuV_2O_6"J.Phys.Soc.Jpn... Vol.69 No.8. 2660-2668 (2000)
[文献書誌] J.Akimitsu et.al.: "The magnetic ordering in the spin ladder compound Sr_<2.5>Ca_<11.5>Cu_<24>O_<41>"Physica.B.. 289-290. 157-160 (2000)
[文献書誌] K.Ohishi et.al.: "Anomalous field dependence of the vortex-core radius and magnetic penetration depth in YNi_2B_2C probed by μSR."Physica.B.. 289-290. 377-380 (2000)
[文献書誌] K.Ishii et.al.: "Appearance of magnetic long-range order in the spin ladder compound La_<1-x>Sr_xCuO_<2.5>"Physica.B.. 289-290. 165-167 (2000)
[文献書誌] K.Ohishi et.al.: "Spatially Modulated Antiferromagnetism in Sr_<2.5>Ca_<11.5>Cu_<24>O_<41> Probed by Muon Spin Relaxation"J.Phys.Soc.Jpn.. Vol.69No.8. 2427-2430 (2000)
[文献書誌] 秋光純: "梯子型超伝導体発見と物性の追究,酸素が作る奇妙な物質"金属酸化物が拓く新しい科学. 114-128 (2000)
[文献書誌] S.Ohsugi et.al.: "Cu NMR and NQR studies on the magnetic order in Sr_<2.5>Ca_<11.5>Cu_<24>O_<41>"Physica,B. 284-288. 1591-1592 (2000)
[文献書誌] A.Zheludev et.al.: "Role of single ion excitations in the mixed-spin quasi-one-dimensional quantum antiferromagnet Nd_2BaNiO_5"Phys.Rev.B. Vol 61No.17. 11601-11612 (2000)
[文献書誌] R.Kadono: "Anomalous local magnetic shielding effect at muon site in Sr_<2.5>Ca_<11.5>Cu_<24>O_<41> and Ce_<0.99>Cu_<2.02>Si_2"physica B. 289-290. 322-325 (2000)
[文献書誌] K.Kakuta et.al.: "Antiferromagnet (Ln,Ca)CuO_<2.5> near the quantum critical point (Ln=Pr,Nd)"Physica B. 289-290. 168-171 (2000)
[文献書誌] N.Ogita et.al.: "Raman scattering of Sr_<14-x>Ca_xCu_<24>O_<41>"Physica,B. 281&282. 955-956 (2000)
[文献書誌] M.Nishi et.al.: "Lattice dynamics of CuGeO_3 by inelastic neutron scattering"J.Phy.Chem.Sol.. 62. 355-356 (2000)
[文献書誌] J.Akimitsu: "Antiferromagnetism and Spin Gap State in the two-leg Ladder System"J.Phys.Chem.Solid. 65. 135-140 (2000)
[文献書誌] R.Kadono et.al.: "Spin Dynamics of 4f Electrons in CeB_6 Studied by Muon Spin Relaxation"J.Phys.Soc.Jpn.. Vol.69No.10. 3189-3192 (2000)
[文献書誌] N.Furukawa et. al.: "Magnon Broadening Effects in Double Layered Manganite La_<1.2>Sr_<1.8>Mn_<207>"Physica B. 291. 324-326 (2000)
[文献書誌] N.Furukawa: "Unconventional one-magnon scattering resistivity in half metals"J.Phys.Soc.Jpn.. 69(7). 1954-1957 (2000)
[文献書誌] T.Akimoto et.al.: "Observation of anomalous single-magnon scattering in half-metallic ferromagnets by chemical pressure control"Phys.Rev.Lett. 85. 3914-3917 (2000)
[文献書誌] H.Nakata et.al.: "ARK : A Pentium II/Linux cluster -A parallel computer system based on commodity PC class hardware"Prog.Theor.Phys.Suppl.. 138. 757-758 (2000)
[文献書誌] J.Kishine et.al.: "Two-Loop Renormalization of the Quasiparticle Weight in Two-Dimensional"Electron Systems,in RECENT PROGRESS IN MANY-BODY THEORIES. Vol.3. 88-91 (2000)
[文献書誌] Y.Motome et.al.: "Critical Temperature of Ferromagnetic Transition in Three-Dimensional Double-Exchange Models"J.Phys.Soc.Jpn.. 69. 3785-3788 (2000)
[文献書誌] C.Honerkamp et.al.: "Breakdown of the Landau-Fermi liquid in Two Dimensions due to Umklapp Scattering"Phys.Rev.B. 63. 35109-35109 (2000)
[文献書誌] S.Yamada et.al.: "Thermopower in Pr_<1-x>Ca_xMnO_3"J.Phys.Soc.Jpn.. 69. 1278-1281 (2000)
[文献書誌] M.Noguchi et.al.: "Synchrotron x-ray-diffraction study of orbital ordering in YVO_3"Phys.Rev.B. 62. R9271-R9274 (2000)
[文献書誌] T.Saito et.al.: "Oprical Study of Metal-Insulator Transition in SmBaCo2O6-d Single Crystal"J.Phys.Soc.Jpn.. 69. 3525-3528 (2000)
[文献書誌] K.Hirota et.al.: "Direct Observation of Antiferro-Quadrupolar Ordering-Resonant X-ray Scattering Study of DyB_2C_2"Phys.Rev.Lett.. 84. 2706-2709 (2000)
[文献書誌] T.Akimoto et.al.: "Orbital stability in the spin-ordered phase of bilayer manganites as investigated by neutron-diffraction measurements"Phys.Rev.B. 61. 11270-11273 (2000)
[文献書誌] M.Kubota et.al.: "Relation between crystal and magnetic structures of the layered manganites La_<2-2x>Sr_<1+2x>Mn_2O_7(0.30【less than or equal】x【less than or equal】0.50)"J.Phys.Soc.Japan. 69. 1606-1609 (2000)
[文献書誌] M.Kubota, et.al.: "Influence of quasi-bi-stripe charge ordering on resistivity and magnetism in the bilayer manganite La_<2-2x>Sr_<1+2x>Mn_2O_7"J.Phys.Soc.Japan. 69. 1986-1989 (2000)
[文献書誌] Y.Moritomo et.al.: "Pressure-induced insulator-metal transition in a bilayer manganite : Pressure control of orbital stability"Phys.Rev.B. 62. 17-20 (2000)

2000 年度 実績報告書

軌道相転移の制御による新物質創製

研究代表者

秋光 純 青山学院大学, 理工学部, 教授 (80013522)

研究成果

[文献書誌] H.Ichikawa et.al.: "Direct Observation of Orbital Ordering in YTiO_3"Physica.B. 281-282. 482-484 (2000)

[文献書誌] S.Ohsugi. et. al.: "Cu NMR and NQR studies on the magnetic order in Sr_<2.5>Ca_<11.5>Cu_<2441>"Physica.B. 284-288. 1591-1592 (2000)

[文献書誌] Y.Gotoh et. al.: "Role of structural modulation in the composite crystal (Sr_2Cu_2O_3)_<0.70>CuO_2, "Sr_<14>Cu_<24>O_<41>" with two-legged spin ladder"Physica C. 341-348. 469-470 (2000)

[文献書誌] T.Nakanishi et. al.: "Upper Critical Field of Spin-Ladder Sr_2Ca_<12>Cu_<24>O_<41>"Physica.B. 281-282. 957-958 (2000)

[文献書誌] D.Braithwaite et. al.: "Upper Critical Field of the Spin Ladder System Sr_<2.5>Ca_<11.5>O_<41>"Solid State Commun.. 114. 533-536 (2000)

[文献書誌] M.Hiroi et.al.: "Study on CuGe_<0.9885>Si_<0.0115>O_3 in High Magnetic Fields by Specific Heat Measurements"Physica B. 281 and 282. 669-670 (2000)

[文献書誌] A.Zheludev et.al.: "Role of Single Ion Excitations in the Mixed-Spin Quasi-One-Dimensional Quantum Antiferromagnet Nd_2BaNiO_5"Phys.Rev.B. Vol.61. 11601-11612 (2000)

[文献書誌] T.Yokoo et.al.: "Magnetic Excitations in the Haldane System R_2BaNiO_5"J.Phys.Soc.Jpn.. 69Suppl.B. 95-101 (2000)

[文献書誌] 永田貴志 et.al.: "梯子格子系超伝導体;(Sr,Ca)_<14>Cu_<24>O_<41>の物性"物性研究. Vol.74 No.4. 357-368 (2000)

[文献書誌] J.Kikuchi et.al: "NMR and Newtron Scattering Studies of Quasi One-Dimensional Magnet CuV_2O_6"J.Phys.Soc.Jpn... Vol.69 No.8. 2660-2668 (2000)

[文献書誌] J.Akimitsu et.al.: "The magnetic ordering in the spin ladder compound Sr_<2.5>Ca_<11.5>Cu_<24>O_<41>"Physica.B.. 289-290. 157-160 (2000)

[文献書誌] K.Ohishi et.al.: "Anomalous field dependence of the vortex-core radius and magnetic penetration depth in YNi_2B_2C probed by μSR."Physica.B.. 289-290. 377-380 (2000)

[文献書誌] K.Ishii et.al.: "Appearance of magnetic long-range order in the spin ladder compound La_<1-x>Sr_xCuO_<2.5>"Physica.B.. 289-290. 165-167 (2000)

[文献書誌] K.Ohishi et.al.: "Spatially Modulated Antiferromagnetism in Sr_<2.5>Ca_<11.5>Cu_<24>O_<41> Probed by Muon Spin Relaxation"J.Phys.Soc.Jpn.. Vol.69No.8. 2427-2430 (2000)

[文献書誌] 秋光純: "梯子型超伝導体発見と物性の追究,酸素が作る奇妙な物質"金属酸化物が拓く新しい科学. 114-128 (2000)

[文献書誌] S.Ohsugi et.al.: "Cu NMR and NQR studies on the magnetic order in Sr_<2.5>Ca_<11.5>Cu_<24>O_<41>"Physica,B. 284-288. 1591-1592 (2000)

[文献書誌] A.Zheludev et.al.: "Role of single ion excitations in the mixed-spin quasi-one-dimensional quantum antiferromagnet Nd_2BaNiO_5"Phys.Rev.B. Vol 61No.17. 11601-11612 (2000)

[文献書誌] R.Kadono: "Anomalous local magnetic shielding effect at muon site in Sr_<2.5>Ca_<11.5>Cu_<24>O_<41> and Ce_<0.99>Cu_<2.02>Si_2"physica B. 289-290. 322-325 (2000)

[文献書誌] K.Kakuta et.al.: "Antiferromagnet (Ln,Ca)CuO_<2.5> near the quantum critical point (Ln=Pr,Nd)"Physica B. 289-290. 168-171 (2000)

[文献書誌] N.Ogita et.al.: "Raman scattering of Sr_<14-x>Ca_xCu_<24>O_<41>"Physica,B. 281&282. 955-956 (2000)

[文献書誌] M.Nishi et.al.: "Lattice dynamics of CuGeO_3 by inelastic neutron scattering"J.Phy.Chem.Sol.. 62. 355-356 (2000)

[文献書誌] J.Akimitsu: "Antiferromagnetism and Spin Gap State in the two-leg Ladder System"J.Phys.Chem.Solid. 65. 135-140 (2000)

[文献書誌] R.Kadono et.al.: "Spin Dynamics of 4f Electrons in CeB_6 Studied by Muon Spin Relaxation"J.Phys.Soc.Jpn.. Vol.69No.10. 3189-3192 (2000)

[文献書誌] N.Furukawa et. al.: "Magnon Broadening Effects in Double Layered Manganite La_<1.2>Sr_<1.8>Mn_<207>"Physica B. 291. 324-326 (2000)

[文献書誌] N.Furukawa: "Unconventional one-magnon scattering resistivity in half metals"J.Phys.Soc.Jpn.. 69(7). 1954-1957 (2000)

[文献書誌] T.Akimoto et.al.: "Observation of anomalous single-magnon scattering in half-metallic ferromagnets by chemical pressure control"Phys.Rev.Lett. 85. 3914-3917 (2000)

[文献書誌] H.Nakata et.al.: "ARK : A Pentium II/Linux cluster -A parallel computer system based on commodity PC class hardware"Prog.Theor.Phys.Suppl.. 138. 757-758 (2000)

[文献書誌] J.Kishine et.al.: "Two-Loop Renormalization of the Quasiparticle Weight in Two-Dimensional"Electron Systems,in RECENT PROGRESS IN MANY-BODY THEORIES. Vol.3. 88-91 (2000)

[文献書誌] Y.Motome et.al.: "Critical Temperature of Ferromagnetic Transition in Three-Dimensional Double-Exchange Models"J.Phys.Soc.Jpn.. 69. 3785-3788 (2000)

[文献書誌] C.Honerkamp et.al.: "Breakdown of the Landau-Fermi liquid in Two Dimensions due to Umklapp Scattering"Phys.Rev.B. 63. 35109-35109 (2000)

[文献書誌] S.Yamada et.al.: "Thermopower in Pr_<1-x>Ca_xMnO_3"J.Phys.Soc.Jpn.. 69. 1278-1281 (2000)

[文献書誌] M.Noguchi et.al.: "Synchrotron x-ray-diffraction study of orbital ordering in YVO_3"Phys.Rev.B. 62. R9271-R9274 (2000)

[文献書誌] T.Saito et.al.: "Oprical Study of Metal-Insulator Transition in SmBaCo2O6-d Single Crystal"J.Phys.Soc.Jpn.. 69. 3525-3528 (2000)

[文献書誌] K.Hirota et.al.: "Direct Observation of Antiferro-Quadrupolar Ordering-Resonant X-ray Scattering Study of DyB_2C_2"Phys.Rev.Lett.. 84. 2706-2709 (2000)

[文献書誌] T.Akimoto et.al.: "Orbital stability in the spin-ordered phase of bilayer manganites as investigated by neutron-diffraction measurements"Phys.Rev.B. 61. 11270-11273 (2000)

[文献書誌] M.Kubota et.al.: "Relation between crystal and magnetic structures of the layered manganites La_<2-2x>Sr_<1+2x>Mn_2O_7(0.30【less than or equal】x【less than or equal】0.50)"J.Phys.Soc.Japan. 69. 1606-1609 (2000)

[文献書誌] M.Kubota, et.al.: "Influence of quasi-bi-stripe charge ordering on resistivity and magnetism in the bilayer manganite La_<2-2x>Sr_<1+2x>Mn_2O_7"J.Phys.Soc.Japan. 69. 1986-1989 (2000)

[文献書誌] Y.Moritomo et.al.: "Pressure-induced insulator-metal transition in a bilayer manganite : Pressure control of orbital stability"Phys.Rev.B. 62. 17-20 (2000)

2000 年度実績報告書

秋光純青山学院大学, 理工学部, 教授 (80013522)