1998 Fiscal Year Annual Research Report

f電子フェルミ面微細電子構造の高分解能角度分解光電子分光

Research Project

Project/Area Number	10440097
Research Institution	Tohoku University
Principal Investigator	高橋隆東北大学, 大学院・理学研究科, 助教授 (00142919)
Co-Investigator(Kenkyū-buntansha)	田中章順東北大学, 大学院・理学研究科, 助手 (40250667)
Keywords	光電子分光 / フェルミ面 / 強相関電子系 / 電子構造 / 超伝導体 / 相転移 / f電子
Research Abstract	旧来型の直流型希ガス放電管をマイクロ波励起新型放電管に交換調整する事で、励起光量の一桁増加を達成し、分解能を目標の10meVに持って行くことに成功した。改良を行った高分解能角度分解光電子分光装置を用いて以下の物質に対して測定を行い、下に示すいくつかの重要な新しい知見を得た。 1. CeSbの磁気相転移に伴うフェルミ面形状の変化を初めて直接観測することに成功し、磁気相転移の機構が異方的p-f混成効果に基づくものであることを見出した。 2. CeSbの参照物質であるf電子を持たないLaSbのバンド構造を決定し、それが小さな電子およびホール面を持つ半金属であることを見出した。このことは、CeSbの電気磁気的性質を説明する異方的p-f混成モデルの出発点が正しいことを示している。 3. CeRhSbおよびCeRhAsにおいて、フェルミ準位上に温度に伴い開閉する微小エネルギー擬ギャップを見出し、これらの物質がf-d軌道の混成の結果実現される「近藤半導体」であることを見出した。 4. 5f電子超伝導体であるUPt_3について測定を行い、価電子帯中のPt5dバンドは一電子近似であるバンド計算で良く再現されるものの、フェルミ準位近傍に位置し物性を支配しているU5f電子は計算に比べ非常に狭いバンドを形成していることを見出した。これは、U5f電子間の電子相関の効果により有効電子質量が増加しているためと結論される。 5. Bi系高温超伝導体のアンダードープから最適ドープ領域試料において、超伝導転移点の上の温度でフェルミ準位上にエネルギーギャップが開いていることを見出し(常伝導擬ギャップと命名)、それが超伝導と関係した前駆現象であることを見出した。

Research Products
(24 results)

All Other

All Publications (24 results)

[Publications] T.Takahashi et al.: "Magnetic phase transition of cesb studied by high-resolution angle-resolved photoemission" J.Magnetism and Magnetic Materials. 177-181. 1027-1028 (1998)
[Publications] H.Kumigashira et al.: "Surface and bulk 4f electionic structure of CeIn_3 and CeSn_3" J.Magnetism and Magnetic Materials. 177-181. 1035-1036 (1998)
[Publications] Hyeong-Do Kim et al.: "High-resolution photoemission study of V_2-yO_3" Physical Review B. 57. 1316-1319 (1998)
[Publications] T.Sato et al.: "Angle-resolved photoemission study of superconducting ladder compound Sr_<14-x>Ca_xCu_<24>O_<41>" J.Physics and Chemistry of Solids. 59. 1912-1916 (1998)
[Publications] H.Fujisawa et al.: "Angle-resolved photoemission spectroscopy of SrCuO_2;Spin-charge separation?" J.Electron Spectroscopy and Related Phenomena. 88-91. 461-465 (1998)
[Publications] H.Fujisawa et al.: "Spin-charge separation in single-chain compound Sr_2CuO_3 studied by angle-resolved photoemission" Solid state Communications. 106. 543-547 (1998)
[Publications] O.ARaki et al.: "Temperolare-dependent core-level x-ray photremission spectroscopy of the organic conductor,(MeCl-DCNQI)_2Cu,(MeBr-DCNQI)_2Cu,..." Physical Review B. 57. 11846-11849 (1998)
[Publications] T.Takahashi et al.: "High-resolution angle-resolved photoemission,study of CeSb and USb" J.Electron Spectroscopy and Related Phenomena. 92. 65-69 (1998)
[Publications] M.R.Norman et al.: "Destruction of the Fermisurface in under doped high-Tc superconductors" Nature. 392. 157-160 (1998)
[Publications] K.Brever et al.: "Photoemission study of the Kondo Insulator Ce_3Bi_4Pt_3" Europhysics Letters. 41. 565-570 (1998)
[Publications] S.Kimura et al.: "4d-4f and 3d-4f resondret photoemision of TmX(X=S.Se.Te)" J.Mag.Mag.Mater.177-181. 349-350 (1998)
[Publications] G.chiaia et al.: "Electronic structure of CeSe probed by resonant photoemission spectroscopy:a test case for the single inopurity Anderson Hamiltonian" Physical Review B. 57. 12030-12035 (1998)
[Publications] E.Z.Kurmaev et al.: "Electronic structure of Sr_2RnO_4:X-ray fluorescence emission study" Physical Review B. 57. 1558-1562 (1998)
[Publications] H.Kumigashira et al.: "High-resolution angle-resolved photoemission study of hasb" Physical Review B. 58. 7675-7680 (1998)
[Publications] Y.Ufuktepe et al.: "Resondust photoemission studies of Thulium monochakogonides around" J.Phys.Soc.Jpn.67. 2018-2026 (1998)
[Publications] T.Yokoya et al.: "Electronic structure of Ce_<1-x>Sr_xTiO_3:Comparison between substitutional and vacancy doping" Physical Review B. 59. 1815-1818 (1999)
[Publications] H.Kumigashira et al.: "High-resolution angle-resolved photoemission study of RSb(R=ha,Ce.U)" Physica B. (in press).
[Publications] T.Ito et al.: "Angle-resolved photoemission Spectroscopy of Upt_3" Physica B. (in press).
[Publications] K.G.Nath et al.: "4d Cove-level resonant photoemission spectroscopy of thylium monochalcogonides around the Tm 3d threshold" J.Electron Spectroscopy and Related Phenomona. 86-91. 369-375 (1998)
[Publications] T.Kinoshita et al.: "Resonant photoemission study of thulium monocholoogenides around the Tm 3d threshald" J.Electron Spectroscopy and Related Phenomena. 88-91. 377-384 (1998)
[Publications] H.Fujisawa et al.: "Angle-resolved photoemission study of Sr_2CuO_3" Physical Review B. (in press).
[Publications] T.Ito et al.: "High-resolution angle-resolved photoemission study of heavy fermion superconductor UPt_3" Physical Review B. (in press).
[Publications] H.Kumigashira et al.: "Spectral Evidence for pseudogep Formation in Konda Insulators CeRh As and CeRhSb" Physical Reviews Letters. (in press).
[Publications] Hyeong-Do Kim et al.: "Surface and buck 4f photoemission spectro of CeIr_2" Physical Review B. (in press).

1998 Fiscal Year Annual Research Report

f電子フェルミ面微細電子構造の高分解能角度分解光電子分光

Principal Investigator

高橋 隆 東北大学, 大学院・理学研究科, 助教授 (00142919)

Research Products

[Publications] T.Takahashi et al.: "Magnetic phase transition of cesb studied by high-resolution angle-resolved photoemission" J.Magnetism and Magnetic Materials. 177-181. 1027-1028 (1998)

[Publications] H.Kumigashira et al.: "Surface and bulk 4f electionic structure of CeIn_3 and CeSn_3" J.Magnetism and Magnetic Materials. 177-181. 1035-1036 (1998)

[Publications] Hyeong-Do Kim et al.: "High-resolution photoemission study of V_2-yO_3" Physical Review B. 57. 1316-1319 (1998)

[Publications] T.Sato et al.: "Angle-resolved photoemission study of superconducting ladder compound Sr_<14-x>Ca_xCu_<24>O_<41>" J.Physics and Chemistry of Solids. 59. 1912-1916 (1998)

[Publications] H.Fujisawa et al.: "Angle-resolved photoemission spectroscopy of SrCuO_2;Spin-charge separation?" J.Electron Spectroscopy and Related Phenomena. 88-91. 461-465 (1998)

[Publications] H.Fujisawa et al.: "Spin-charge separation in single-chain compound Sr_2CuO_3 studied by angle-resolved photoemission" Solid state Communications. 106. 543-547 (1998)

[Publications] O.ARaki et al.: "Temperolare-dependent core-level x-ray photremission spectroscopy of the organic conductor,(MeCl-DCNQI)_2Cu,(MeBr-DCNQI)_2Cu,..." Physical Review B. 57. 11846-11849 (1998)

[Publications] T.Takahashi et al.: "High-resolution angle-resolved photoemission,study of CeSb and USb" J.Electron Spectroscopy and Related Phenomena. 92. 65-69 (1998)

[Publications] M.R.Norman et al.: "Destruction of the Fermisurface in under doped high-Tc superconductors" Nature. 392. 157-160 (1998)

[Publications] K.Brever et al.: "Photoemission study of the Kondo Insulator Ce_3Bi_4Pt_3" Europhysics Letters. 41. 565-570 (1998)

[Publications] S.Kimura et al.: "4d-4f and 3d-4f resondret photoemision of TmX(X=S.Se.Te)" J.Mag.Mag.Mater.177-181. 349-350 (1998)

[Publications] G.chiaia et al.: "Electronic structure of CeSe probed by resonant photoemission spectroscopy:a test case for the single inopurity Anderson Hamiltonian" Physical Review B. 57. 12030-12035 (1998)

[Publications] E.Z.Kurmaev et al.: "Electronic structure of Sr_2RnO_4:X-ray fluorescence emission study" Physical Review B. 57. 1558-1562 (1998)

[Publications] H.Kumigashira et al.: "High-resolution angle-resolved photoemission study of hasb" Physical Review B. 58. 7675-7680 (1998)

[Publications] Y.Ufuktepe et al.: "Resondust photoemission studies of Thulium monochakogonides around" J.Phys.Soc.Jpn.67. 2018-2026 (1998)

[Publications] T.Yokoya et al.: "Electronic structure of Ce_<1-x>Sr_xTiO_3:Comparison between substitutional and vacancy doping" Physical Review B. 59. 1815-1818 (1999)

[Publications] H.Kumigashira et al.: "High-resolution angle-resolved photoemission study of RSb(R=ha,Ce.U)" Physica B. (in press).

[Publications] T.Ito et al.: "Angle-resolved photoemission Spectroscopy of Upt_3" Physica B. (in press).

[Publications] K.G.Nath et al.: "4d Cove-level resonant photoemission spectroscopy of thylium monochalcogonides around the Tm 3d threshold" J.Electron Spectroscopy and Related Phenomona. 86-91. 369-375 (1998)

[Publications] T.Kinoshita et al.: "Resonant photoemission study of thulium monocholoogenides around the Tm 3d threshald" J.Electron Spectroscopy and Related Phenomena. 88-91. 377-384 (1998)

[Publications] H.Fujisawa et al.: "Angle-resolved photoemission study of Sr_2CuO_3" Physical Review B. (in press).

[Publications] T.Ito et al.: "High-resolution angle-resolved photoemission study of heavy fermion superconductor UPt_3" Physical Review B. (in press).

[Publications] H.Kumigashira et al.: "Spectral Evidence for pseudogep Formation in Konda Insulators CeRh As and CeRhSb" Physical Reviews Letters. (in press).

[Publications] Hyeong-Do Kim et al.: "Surface and buck 4f photoemission spectro of CeIr_2" Physical Review B. (in press).

高橋隆東北大学, 大学院・理学研究科, 助教授 (00142919)