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1996 Fiscal Year Final Research Report Summary

Polymorphism and Magnetism of Organic Radical Crystals

Research Project

Project/Area Number 07640767
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field 機能・物性・材料
Research InstitutionScience University of Tokyo in Yamaguchi

Principal Investigator

KINOSHITA Minoru  Science University of Tokyo Faculty of Science and Engineering Professor, 基礎工学部, 教授 (40011530)

Project Period (FY) 1995 – 1996
KeywordsOrganic ferromagnet / Ferromagnetic interactoin / Phase transition / Polymorphism / Galvinoxyl / p-NPNN / Hydrogen bond / Crystal structure
Research Abstract

Organic radicals of galvinoxyl and p-nitrophenyl nitronyl nitroxide (p-NPNN) playd crucial roles in the discovery of purly organic ferromagnet. These two and some related compounds exhibit polymorphism and variety of magnetism. This was quite important in elucidating the mechanism of magnetic interactions, because the polymorphic forms are closely related to one another in crystal structure. Galvinoxyl exhibits ferromagnetic interaction in the high temperature phase, but it is non-magnetic below 85K.The crystal structure is known for the high temperature phase, but it is unknown at low temperature. In this project, we have tried to determine the crystal structure of its low temperature phase. We could obtain the x-ray diffraction pattern at about 10K.However, the crystal became twinned and extra spots appeared prevented us from final analysis of the pattern. We then tried to find a way to cool the crystals without crushing at the phase transtion temperature. Various ways could not succeed. During the course of testing various ways, however, we could succeed in finding the way to surpress the phase transition by applying pressure and to maintain the ferromagnetic interaction down to low temperature. As for the phase transitions in p-NPNN,model calculation indicates an importance of librational motion of the molecules in exhibiting the polymorphism.

  • Research Products

    (13 results)

All Other

All Publications (13 results)

  • [Publications] M. Kinoshita: "Eletrical conductivity and superconductivity of metal phosphides with Skutterruditetype structure prepared at high pressure" Journal of Physics and Chemistry of Solids. 57. 211-216 (1996)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] M. Kinoshita: "Pressure effect on the Curie temperature and intermolecular interactions in organic ferromagnet β-phase p-NPNN" Molecular Crystals and Liquid Crystals. 279. 115-122 (1996)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] M. Kinoshita: "Pressure effects on intermolecular interactions of the organic ferromagnetic crystalline β-phase p-nitrophenyl nitronyl nitroxide" Physical Review. B53. 3374-3380 (1996)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] M. Kinoshita: "Structure and properties of titanium-including complex,tris(tetramethyltetrathiafulvalene)di-μ-fluoro-bis[tetrafluorotitanate(IV)], (TMTTF)_3・Ti_2F_<10>" Bulletin of the Chemical Society of Japan. 69. 1869-1873 (1996)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] M. Kinoshita: ""Molecular Magnertism : From Molecular Assembies to the Devices"" Kluwer Academic Publishers(Dordrecht/Boston/London), 590 (1996)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] M. Kinoshita: ""Organic Molecular Solids-Properties and Applications"" CRC Press (Boca Raton,New York,USA), 426 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] K.Konishi, K.Takeda, M.Tamura and M.Kinoshita: "Pressure effect on the Curie temperature and inter-molecular interactions in organic ferromagnet beta-phase p-NPNN" Mol. Cryst. Liq. Cryst.279. 115-122 (1996)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] K.Takeda, K.Konishi, M.Tamura and M.Kinoshita: "Pressure effects on intermolecular interactions of the organic ferromagnetic crystalline beta-phase p-nitrophenyl nitronyl nitroxide" Phys. Rev.B53(6). 3374-3380 (1996)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] H.Akutsu, K.Ozaki, T.Ozaki, K.Nozawa, M.Kinoshita, K.Kozawa and T.Uchida: "Structure and properties of titanium-including complex, tris (tetramethyltetrathia-fulvalene) di-m-fluoro-bis [tetrafluorotitanate (IV)], (TMTTF)_3Ti_2F_<10>." Bull. Chem. Soc. Japan. 69(7). 1869-1873 (1996)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Y.Kusaba, M.Tamura, Y.Hosokoshi, M.Kinoshita, H.Sawa, R.Kato and H.Kobayashi: "Isolation of crystals of a planar nitronyl nitroxide radical : 2-phenyl-benzimida-zol-1-yl-N,N'-dioxide (PBIDO)." J.Mater. Chem. accepted. (1997)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] M.Kinoshita: Organic magnetic materials with cooperative magnetic properties, in "Molecular Magnetism. From Molecular Assemblies to the Devices", ed. by E.Coronado, P.Delhaes, D.Gatteschi and J.S.Miller. NATO ASI Series E,vol.321, pp.449-472, Kluwer Academic Publishers, (1996)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] M.Kinoshita: Magnetic Properties of Organic Solids, in "Organic Molecular Solids-Properties and Applications", et. by W.Jones. CRC Press (Boca Raton, New York, USA), 379-414 (1996)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] M.Kinoshita: Magnetism of Stable Organic Radical Crystals, in "Organic Conductive Molecules and Polymers", ed. by H.S.Nalwa. Vol.1, John Wiley & Sons, Ltd., (1997)

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

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Published: 1999-03-09  

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