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Unified view for pressure-induced successive changes from amorphization to re-entrant crystallization

Research Project

Project/Area Number 16540343
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field Mathematical physics/Fundamental condensed matter physics
Research InstitutionEhime University

Principal Investigator

FUCHIZAKI Kazuhiro  Ehime University, Department of Physics, Professor, 理学部, 教授 (10243883)

Project Period (FY) 2004 – 2005
Project Status Completed (Fiscal Year 2005)
Budget Amount *help
¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 2005: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2004: ¥800,000 (Direct Cost: ¥800,000)
Keywordspressure / structural phase transition / amorphization / molecular crystal / cluster / optimization / polymerization
Research Abstract

A new idea of "thermodynamic optimization for spatial configuration among elements with variable size" is proposed. On the basis of this idea the reporter has tried to explain a series of structural changes induced by uploading pressure. To this end, a molecular crystal tin tetraiodide was chosen as a prototype substance, which undergoes pressure-induced amorphization followed by re-entrant crystallization. If tin atoms are assumed to occupy the tetrahedral interstitial sites of the host lattice made of iodines, frustration will come up in finding possible occupation sites as far as the tin does always take four iodines as nearest neighbors. According to this rule the lower-pressure phase structure automatically appears as a case without any frustration. However, frustration develops with increasing tin population. The local energy of the frustrated site becomes higher as compared to nonfrustated site. The Hamiltonian can then be written down by suitably assigning the local energies. T … More he series of structural variations were thus qualitatively explained by minimizing the free energy obtained through the Hamiltonian.
The idea can be adapted to describe the physical origin of polyamorphism. It is naturally inferred that a pressure-induced liquid-to-liquid transition will take place in tin tetraiodide. In fact, from the melting curve of the low-pressure crystalline phase was found to have a break at around 1.5 GPa, beyond which the melting curve becomes almost flat. This suggests that the density of the low-pressure liquid differs from that on the higher-pressure side. Finally, we have succeeded in showing direct evidence for the existence of the two liquids with different local structures by conducting in situ synchrotron x-ray diffraction experiments. The present idea yields, when treated within mean-field approximation, a regular solution treatment. The phase diagram of tin tetraiode was constructed within this framework, which included a new critical point and spinodal lines. Less

Report

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

    (11 results)

All 2006 2004

All Journal Article (11 results)

  • [Journal Article] Murnaghan's Equation of State Revisited2006

    • Author(s)
      Kazuhiro Fuchizaki
    • Journal Title

      Journal of Physical Society of Japan 75

    • NAID

      110004704679

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Murnaghan's Equation of State Revisited2006

    • Author(s)
      Kazhiro Fuchizaki
    • Journal Title

      Journal of Physical Society of Japan 75

    • NAID

      110004704679

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Murnaghan's equation of state revisited2006

    • Author(s)
      Kazuhiro Fuchizaki
    • Journal Title

      Journal of Physical Society of Japan 75・3(印刷中)

    • NAID

      110004704679

    • Related Report
      2005 Annual Research Report
  • [Journal Article] 圧力誘起非晶質化の発現機構2004

    • Author(s)
      渕崎員弘
    • Journal Title

      日本板硝子材料工学助成会誌 22

      Pages: 150-162

    • 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 low-pressure crystalline-liquid phase boundary of SnI_42004

    • Author(s)
      Kazuhiro Fuchizaki
    • Journal Title

      Journal of Chemical Physics 120

      Pages: 11196-11199

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Effect of octupole-octupole interactions of on the thermodynamic stability of the low-pressure crystalline state of SnI_4 molecular crystal2004

    • Author(s)
      Kazuhiro Fuchizaki
    • Journal Title

      Solid State Communications 132

      Pages: 305-308

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Physical Mechanism of Pressure-Induced Amorphization2004

    • Author(s)
      Kazuhiro Fuchizaki
    • Journal Title

      Nippon Sheet Glass Foundation for Materials Science and Engineering Report 22

      Pages: 150-162

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Determination of low-pressure crystalline-liquid phase boundary of InI_42004

    • Author(s)
      Kazuhiro Fuchizaki
    • Journal Title

      Journal of Chemical Physics 120

      Pages: 11196-11199

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Effect of octupole-octupole interactions on the thermodynamic stability of low-pressure crystalline state of SnI_4 molecular crystal2004

    • Author(s)
      Kazuhiro Fuchizaki
    • Journal Title

      Solid State Communication 132

      Pages: 305-308

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Determination of low-pressure crystalline-liquid phase boundary of SnI_42004

    • Author(s)
      K.Fuchizaki
    • Journal Title

      Journal of Chemical Physics 120・23

      Pages: 11196-11199

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Effect of octupole-octupole interactions on the thermodynamic stability of the low-pressure crystalline state of SnI_4 molecular crystals2004

    • Author(s)
      K.Fuchizaki
    • Journal Title

      Solid State Communications 132

      Pages: 305-308

    • Related Report
      2004 Annual Research Report

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Published: 2004-04-01   Modified: 2016-04-21  

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