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

1986 Fiscal Year Final Research Report Summary

Study of the Ground State Properties in Random Magnetic Systems

Research Project

Project/Area Number 60460023
Research Category

Grant-in-Aid for General Scientific Research (B)

Allocation TypeSingle-year Grants
Research Field 固体物性
Research InstitutionThe Institute of Physical and Chemical Research(RIKEN) (1986)
Hokkaido University (1985)

Principal Investigator

KATSUMATA Koichi  RIKEN, その他, 研究員 (90002104)

Project Period (FY) 1985 – 1986
KeywordsRandom Magnetic System / Ground State / Spin-glass / Competing Spin Anisotropies / OAF Phase / リエントラントスピングラス
Research Abstract

It is the aim of the present project to clarify the ground state properties of the random magnetic systems with competing spin anisotropies and with competing exchange interactions.
For the study of the competing spin anisotropies system, we have chosen the materials, <Fe_(1-x)> <Co_x> <Cl_2> ・2 <H_2O> (FCC2) , <Fe_(1-x)> <Co_x> <Cl_2> (FCC) and <Fe_(1-x)> <Co_x> <Br_2> (FCB). It is found from the neutron scattering study on FCC2 that the spin components are totally decoupled. FCC2 is the first example of an ideal antiferromagnet with competing spin anisotropies. We have found <Fe^(2+)> localized magnetic excitations in the Co-rich antiferromagnetic phase of FCC2 from the ESR experiments at very high frequency and field. From the analysis of the ESR experiments, it is shown that the <Fe^(2+)> spins make a large angle with the <Co^(2+)> spins even in the Co-rich phase. We have performed similar studies on FCC and FCB. These results give us important informations on the spin orderings and the ground state properties of the random magnets with competing spin anisotropies.
For the study of the competing exchange interactions system, we have chosen the random mixture of a quasi-two-dimensional(2d) ferromagnet <Rb_2> <CrCl_4> and antiferromagnet <Rb_2> <MnCl_4> . The single crystals of <Rb_2> <Mn_(1-x)> <Cr_x> <Cl_4> grown for this study have been characterized by means of susceptibility and ESR measurements. It is found that the random magnet is a typical example of a quasi-2d XY spin-glass(SG). No material has been reported that exhibits a 2d XY SG behavior, and <Rb_2> <Mn_(1-x)> <Cr_x> <Cl_4> is the first example of a 2d XY SG. In the Cr-rich concentration region, we found a re-entrant spin-glass(RSG) transition. The NMR and neutron scattering experiments show that the zero field cooled RSG state consists of ferromagnetic domains and vortices. These results give us an important information on the ground state properties of the 2d XY SG.

  • Research Products

    (16 results)

All Other

All Publications (16 results)

  • [Publications] 勝又紘一: Phys.Rev.B. 31. 316-320 (1985)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 勝又紘一: Solid State Commun.54. 429-432 (1985)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 勝又紘一: J.Phys.Soc.Jpn.54. 1244-1247 (1985)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 勝又紘一: J.Mag.Mag.Mat.54-57. 43-44 (1986)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 勝又紘一: J.Mag.Mag.Mat.54-57. 75-76 (1986)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 久保英範: J.Phys.Soc.Jph.55. 3301-3304 (1986)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 勝又紘一: Solid State Commun.61. 659-663 (1987)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 勝又紘一: Phys.Rev.B.

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] K.Katsumata: "Successive Ising Phase Transitions in a Random Antiferromagnet with Competing Anisotropies" Phys. Rev. B. 31. 316-320 (1985)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] K.Katsumata: " <Fe^(2+)> Localized Excitations in the Random Antiferromagnet with Competing Spin Anisotropies, <Fe_((1-x))> <Co_x> <Br_2> " Solid State Commun.54. 429-432 (1985)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] K.Katsumata: " <Fe^(2+)> Localized Excitations in <Fe_((1-x))> <Co_x> <Cl_2> ・ <2H_2O> " J. Phys. Soc. Jpn.54. 1244-1247 (1985)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] K.Katsumata: "Localized magnetic Excitations in Random Systems with Competing Spin Anisotropies" J. Mag. Mag. Mat.54-57. 43-44 (1986)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] K.Katsumata: "Re-Entrant Spin Glass Transition in a Randomly Mixed Insulating Ferromagnet and Antiferromagnet" J. Mag. Mag. Mat.54-57. 75-76 (1986)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] H.Kubo: "Chlorine NMR in the Re-Entrant Spin-Glass State of the Quasi-Two-Dimensional XY System <Rb_2> <Mn_(1-x)> <Cr_x> <Cl_4> " J. Phys. Soc. Jpn.55. 3301-3304 (1986)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] K.Katsumata: " <Fe^(2+)> Localized Excitation and Spin Orientation in <Fe_(1-x)> <Co_x> <Cl_2> " Solid State Commun.61. 659-663 (1987)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] K.Katsumata: "Phase Transitions in a Quasi-Two-Dimensional XY Random Magnetic System" Phys. Rev. B.

    • Description
      「研究成果報告書概要(欧文)」より

URL: 

Published: 1988-11-10  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi