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1993 Fiscal Year Final Research Report Summary

Studies on the precursor phenomena and the relaxation processes of melting transitions of crystals by a fluorescence

Research Project

Project/Area Number 04640329
Research Category

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

Allocation TypeSingle-year Grants
Research Field 固体物性
Research InstitutionTHE UNIVERSITY OF ELECTRO-COMMUNUCATIONS

Principal Investigator

SHIGENARI Takeshi  Univ.Electro-Commun., Professor, 電気通信学部, 教授 (90017335)

Co-Investigator(Kenkyū-buntansha) ABE Kohji  Univ.Electro-Commun., Research Assis., 電気通信学部, 助手 (20183139)
TAKEUCHI Yoshio  Kyorin Univ., Lecturer, 医学部・物理教室, 講師 (40086616)
SASAKI Yukihiko  Univ.Electro-Commun., Assoc.Prof., 電気通信学部, 助教授 (90017385)
Project Period (FY) 1992 – 1993
KeywordsPhase Transition / Fluorescence / Fluctuation / Pico-second Lasers / Precursor / Ice / Sucurose / Biphenyl / Light Scattering
Research Abstract

Using a newly developed method for the studies on the dynamic of phase transitions, the following results were obtained.
(1).A molecular crystal 'Sucrose' was investigated with a pico-second pulsed laser. It was found the lifetime of the fluorescence sharply decreases as the melting point is approached. By comparing with the X-ray study, it was found that the onset of the observed shortening from a temparature about 25K below Tm was an indication of the collapsing process of the regular crystal structure into an amorphous state. This would be the first measurement of a precursor of a melting transition by light.
(2) A single crystal of ice(Ih) doped with 2-naphthol(2-C8H10(0H)) molecules was grown. The fluorescence lifetime measurements recealed that a stepwise decrease of lifetime from 5ns to 2ns occurs between 130K and 200K.The behavior was analyzed by a model which takes into account the relaxation of the proton configurations in the neighborhood of the naphthol molecules. The analysis allowed us to estimate the activation energy for the generation of L-defects in ice.
(3) A structural phase transition of a single crystal biphenyl was investigated by a similar method. The lifetime shows a minimum at the transition temperature Tc=40K, where biphenyl undergoes a second order incommensurate phase transition. In conrast to the significant change in the lifetime of the broadband fluorescence, a sharp zero-phono line at lambda=533nm was found to have a rather long lifetime without any critical temperature depenedence.
All the results confirmed that that the present method can be a sensitive probe of fluctuations associated with the phase transitions and would be able to be applied to variety of phase transitions. The results were reported, e.g.in the 8th International Meeting on Ferroelectricity and will appear in several journal(in press and submitted).

  • Research Products

    (12 results)

All Other

All Publications (12 results)

  • [Publications] K.Morita,K.Shinjo,Qi Ping,K.Abe and T.Shigenari: "“Precursor of a Melting Transition:Fluorescence and Light Scattering Studies of a Sucrose Crystal"." Ferroelectrics.(in press). (1994)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] T.Shigenari et al.: "“Effect of Fluctuations on the Fluorescence Lifetime in Strong First Order Transitions."" Ferroelectrics.(in press). (1994)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] K.Abe,A.Kakuho,T.Shigenari,Y.Sasaki and Y.Takeuchi: "Macroscopic Symmetry of the Incommensurate Phase of Quartz." Ferroelectrics.(in press). (1994)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] T.Shigenari,E.Kojima,Y.Ino and K.Abe: "Detection of a Precursor in a Strong First Order Structual Phase Transition by a Fluorescence-Lifetime Measurement." Phys.Rev.Lett.66. 2112-2115 (1991)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] T.Shigenari,K.Abe,Y.Ino,K.Morita and E.Kojima: "Critical Speeding-up of the Flourescence Lifetime near the Structural Phase Transition." Springer Proc.in Phys.Vibrational Spectroscopy Proc.5th International conf.on Time-Resolved. 68. 282-283 (1992)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] M.Vallade,K.Abe,B.Berge and T.Shigenari: "Evidence of Acoustic Phonon Modes in the Light Scattering spectrum of Incommensurate Quartz." J.Phys.Condensed Matter.4. 9931-9938 (1992)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] T.Shigenari, E.Kojima, Y.Ino and K.Ae: "Detection of a Precursor in a Strong First Order Structual Phase Transition by a Fluorescence-Lifetine Measurement" Phys.Rev.Lett.66. 2112-2115 (1991)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] T.Shigenari, K.Abe, Y.Ino, K.Morita, and E.Kojima: "Critical Speeding-up of the Fluorescence Lifetime near the stractural Phase Transition" Proc.5th International conf.on time-Resolved vibration Spectroscopy Springer Proc.in Phys.68. 282 (1992)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] K.Morita, K.Shinjo, Qi Ping, K.Abe and T.Shigenari: ""Precursor of a Melting Transition Fluorescence and Light Scattering Studies of a sucrose crystal"" in press in Ferroelectrics.

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] T.Shigenari, K.Abe, K.Morita, Qi Ping and E.Kojima: ""Effect of Fluctuations on the Fluorescence Lifetime in Strong First Order Transitions"" in press in Ferroelectrics.

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] T.Shigenari, K.Abe, K.Morita, Qi Ping, E.Kojima and H.Ino: ""Recursor of a Strong First Order Phase Transition : Critical Speeding-up of the Fluorescence Lifetime in the alpha-beta Transition of Resorcinol."" submitted to J.Phys.Condensed Matter.

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] K.Shinjou, K.Morita, K.Abe and T.Shigenari: ""Lifetime of the impurity-induced fluorescence and zero-phonon line emission in a Biphenyl crystal"" submitted to Ferroelectrics.

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

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Published: 1995-03-27  

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