• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to previous page

Theory on Metal-Insulator Transition in Transition Metal Compounds

Research Project

Project/Area Number 16540318
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field Condensed matter physics II
Research InstitutionHIROSHIMA UNIVERSITY

Principal Investigator

TANAKA Arata  Hiroshima University, Graduate School of Advanced Sciences of Matter, Research Associate, 大学院・先端物質科学研究科, 助手 (70253052)

Project Period (FY) 2004 – 2005
Project Status Completed (Fiscal Year 2005)
Budget Amount *help
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 2005: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2004: ¥1,400,000 (Direct Cost: ¥1,400,000)
KeywordsMetal-Insulator Transition / Transition Metal Compounds / Orbital Degree of Freedom / Intra-atomic Exchange Interaction / Orbital Order / Charge Order / High-Energy Spectroscopy
Research Abstract

The purpose of this research is to reconsider electronic states and metal-insulator transitions in typical strongly correlated electron systems aided by information obtained from newly developed experimental technique such as high-energy spectroscopy. We have investigated 3d transition-metal oxides which exhibit metal-insulator transitions V_2O_3,VO_2,Ti_2O_3,Fe_3O_4 and also those with the perovskite structure. The followings are the outline of the results.
1)Charge and orbital ordering and the Verwey transition in magnetite (Fe_3O_4) have been discussed with a spinless three-band Hubbard model Complex-orbital orders with noncollinear orbital moments, where the occupied t_<2g> orbitals with minority spin are described by a linear combination of the yz, zx and xy orbitals with complex number coefficients, are found to be stabilized. From the results, the transition is expected to be caused by a strong electron-lattice coupling and the resultant modification of the complex- orbital order … More ing.
2)Recently, resonant soft x-ray diffraction at the NiL_<2,3> absorption edge is observed in La_<1.8>Sr_<0.2>NiO_4. From the analysis with a configuration-interaction cluster model, we found that both the antiferromagnetic order and the charge-order superstructure resides within the NiO_2 layers ; the holes are mainly located on in-plane oxygens surrounding a divalent Ni ion site with the spins coupled antiparallel in dose analogy to Zhang-Rice singlets in the cuprates.
3)The metal-insulator transitions (MIT) in VO_2 and Ti_2O_3 have been investigated in connection with the on-site exchange interaction and the lattice distortion on the basis of the many-body theory. The mechanism on the MIT can be understood from a unified viewpoint, where the transitions are caused by a change in the electron configuration of doubly occupied sites from an S=1 Hund's coupling state to a low-spin S=0 state driven by an increase in the level splitting among the t_<2g> orbitals originating from the lattice distortion. Less

Report

(3 results)
  • 2005 Annual Research Report   Final Research Report Summary
  • 2004 Annual Research Report
  • Research Products

    (22 results)

All 2006 2005 2004 Other

All Journal Article (22 results)

  • [Journal Article] Complex-Orbital Ordering and Verwey Transition in Fe_3O_42006

    • Author(s)
      宇津 恒 他
    • Journal Title

      Journal of The Physical Society of Japan 75

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Ti 3d Orbital Change across Metal-Insulator Transition in Ti_2O_3 : Polarization on-Dependent Soft Absorption Spectroscopy at Ti 2p Edge2006

    • Author(s)
      佐藤 仁 他
    • Journal Title

      Journal of The Physical Society of Japan 75

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Complex-Orbital Ordering and Verwey Transition in Fe_3O_42006

    • Author(s)
      Hisashi Uzu, Arata Tanaka
    • Journal Title

      J.Phys.Soc.Jpn. 75

    • NAID

      110004729247

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Ti 3d Orbital Change across Metal-Insulator Transition in Ti_2O_3 : Polarization-Dependent Soft X-ray Absorption Spectroscopy at Ti 2p Edge2006

    • Author(s)
      Hitoshi Sato et al.
    • Journal Title

      J.Phys.Soc.Jpn. 75

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Orbital-Assisted Metal-Insulator Transition in VO_22005

    • Author(s)
      M.W.Haverkort 他
    • Journal Title

      Physical Review Letter 95

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Annual Research Report 2005 Final Research Report Summary
  • [Journal Article] Spectroscopy of Stripe Order in La_1.8Sr_0.2NiO_4 Using Resonant Soft X-Ray Diffraction2005

    • Author(s)
      C.Schuessler-Langeheine 他
    • Journal Title

      Physical Review Letter 95

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Determination of the Orbital Moment and Crystal-Field Splitting in LaTiO_32005

    • Author(s)
      M.W.Haverkort et al.
    • Journal Title

      Phys.Rev.Lett. 94

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Orbital-Assisted metal-Insulator Transition in VO_22005

    • Author(s)
      M.W.Haverkort et al.
    • Journal Title

      Phys.Rev.Lett. 95

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Spectroscopy of Stripe Order in La_<1.8>Sr_<0.2>NiO_4 Using Resonant soft X-Ray Diffraction2005

    • Author(s)
      C.Schuessler-Langeheine et al.
    • Journal Title

      Phys.Rev.Lett. 95

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Spectroscopy of Stripe Order in La_<1.8>Sr_<0.2>NiO_4 Using Resonant Soft X-Ray Diffraction2005

    • Author(s)
      C.Schuessler-Langeheine 他
    • Journal Title

      Physical Review Letter 95

    • Related Report
      2005 Annual Research Report
  • [Journal Article] theory on Metal-Insulator Transitions and Inverse Photoemission Spectroscopy in VO_2 and Ti_2O_32004

    • Author(s)
      田中 新
    • Journal Title

      Physica B : Condensed Matter 351

      Pages: 240-244

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Determination of the Orbital Moment and Crystal-Field Splitting in LaTio_32004

    • Author(s)
      M.W.Haverkort 他
    • Journal Title

      Physical Review Letter 94

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Theory on Metal-Insulator Transitions and Inverse Photoemission Spectroscopy in VO_2 and Ti_2O_32004

    • Author(s)
      Arata Tanaka
    • Journal Title

      Physica B 351

      Pages: 240-244

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] On the Metal-Insulator Transitions in VO_2 and Ti_2O_3 from a Unified Viewpoint2004

    • Author(s)
      田中 新
    • Journal Title

      Journal of The Physical Society of Japan 73

      Pages: 152-162

    • NAID

      110001954706

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Theory on Metal-Insulator Transitions and Inverse Photoemission Spectroscopy in VO_22004

    • Author(s)
      田中 新
    • Journal Title

      Physica B 351

      Pages: 240-244

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Magnetic circular dichroism in Fe 2p resonant photoemission of magnetite2004

    • Author(s)
      J.Chen他
    • Journal Title

      Physical Review B 69

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Charge and Complex Orbital Ordering in Fe_3O_4

    • Author(s)
      Hisashi Uzu, Arata Tanaka
    • Journal Title

      Physica B (in press)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Theory on Photoemission and Inverse Photoemission Spectra in VO_2

    • Author(s)
      Arata Tanaka
    • Journal Title

      Physica B (in press)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Charge and complex orbital ordering in Fe_3O_4

    • Author(s)
      H.Uzu 他
    • Journal Title

      Physica B : Condensed Matter (掲載決定)

    • Related Report
      2005 Annual Research Report
  • [Journal Article] Theory on photoemission and inverse photoemission spectra in VO_2

    • Author(s)
      A.Tanaka
    • Journal Title

      Physica B : Condensed Matter (掲載決定)

    • Related Report
      2005 Annual Research Report
  • [Journal Article] Complex-Orbital Ordering and Verwey Transition in Fe_3O_4

    • Author(s)
      H.Uzu 他
    • Journal Title

      Journal of the Physical Society of Japan (掲載決定)

    • Related Report
      2005 Annual Research Report
  • [Journal Article] Ti 3d orbital switching at the metal-insulator transition, in Ti_2O_3 : polarization-dependent soft x-ray absorption spectroscopy at Ti 2p edge

    • Author(s)
      H.Sato 他
    • Journal Title

      Journal of the Physical Society of Japan (掲載決定)

    • Related Report
      2005 Annual Research Report

URL: 

Published: 2004-04-01   Modified: 2020-05-15  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi