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2004 Fiscal Year Final Research Report Summary

Study of Photoinduced Phase Transition in an Organic Radical Crystal with Strong Correlated Electronic System

Research Project

Project/Area Number 15340094
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Research Field Condensed matter physics I
Research InstitutionNational University Corporation Yokohama National University

Principal Investigator

TAKEDA Jun  National University Corporation Yokohama National University, Graduate School of Engineering, Associate Professor, 大学院・工学研究院, 助教授 (60202165)

Co-Investigator(Kenkyū-buntansha) OHNO Kaoru  National University Corporation Yokohama National University, Graduate School of Engineering, Professor, 大学院・工学研究院, 教授 (40185343)
KODAIRA Tetsuya  National University Corporation Yokohama National University, National Institute of Advanced Science and Technology, Senior Research Scientist, 界面ナノアーキテクトニクス研究センター, 主任研究員 (40356994)
Project Period (FY) 2003 – 2004
KeywordsOrganic Radical / TTTA / Photoinduced Phase Transition / Mott Insulator / Magnetic Phase Transition / Two-Photon Excitation / First Principle Calculation
Research Abstract

Since a large first order magnetic phase transition with a wide thermal hysteresis loop over wide temperature range was found in 1,3,5-trithia-2,4,6-triazapentalenyl(TTTA) crystal, an organic radical crystal is expected to be a new type of strong correlated materials suitable for studying photoinduced phase transition(PIPT) phenomena. In this research, we first experimentally and theoretically investigated the PIPT phenomena as well as electronic and magnetic structures of TTTA.
We found that the photoexcitations of the charge-transfer and intramolecular π-πtransition bands (i.e.one-photon excitations) induce a low-temperature(LT) diamagnetic to high-temperature(HT) paramagnetic phase transition with a clear threshold excitation density. This nonlinear behavior shows that the photoexcitations create the HT phase clusters as precursors, and subsequently, if the total size of the clusters is beyond a critical value, the macroscopic HT order is formed in the LT phase crystal. We also found that two-photon excitation optically induces the diamagnetic to paramagnetic phase transition with large nonlinear response.
We investigated theoretically the crystal structures as well as electronic structures by means of the ab-initio molecular dynamics method based on the local density approximation. We found that the LT phase is a Peierls insulator while the HT phase is a Mott insulator.
We also developed a femtosecond real-time pump-probe imaging spectroscopy applicable to irreversible photoreactions such as the PIPT in solids, which allows real-time mapping of frequency-and time-resolved transient absorbance in a wide spectral and temporal region at once.

  • Research Products

    (16 results)

All 2004 2003 Other

All Journal Article (16 results)

  • [Journal Article] Relaxation and Diffusion of Photoexcited Carriers in ZnO Epitaxial Thin Films2004

    • Author(s)
      J.Takeda, K.Takagi, T.Okabe, H.J.Ko, T.Yao
    • Journal Title

      phys.stat.sol.(c) 1

      Pages: 678-681

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Conversion of an Electron-Hole Plasma into a High Density Excitonic State in ZnO Epitaxial Thin Films2004

    • Author(s)
      Y.Toshine, J.Takeda, H.J.Ko, T.Yao
    • Journal Title

      phys.stat.sol.(c) 1

      Pages: 839-842

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] 光物性の基礎と応用 第10回 測定法(7)-高速分光-2004

    • Author(s)
      武田 淳
    • Journal Title

      オプトロニクス 274

      Pages: 178-183

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Electronic Structures of the TTTA Molecular Crystal2004

    • Author(s)
      M.Furuya, K.Ohno, J.Takeda, Y.Kawazoe
    • Journal Title

      Trans.Mater.Res.Soc.Jpn. 29

      Pages: 3719-3722

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Photoinduced Intramolecular Proton Transfer in 2- and 4-(2,4-Dinitrobenzyl)-pyridine2004

    • Author(s)
      J.Takeda, A.Nashiro, S.Kurita
    • Journal Title

      J.Lumin. 108

      Pages: 245-249

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Femtosecond Real-Time Pump-Prove Imaging Spectroscopy2004

    • Author(s)
      N.Furukawa, C.E.Mair, V.D.Kleiman, J.Takeda
    • Journal Title

      Appl.Phys.Lett. 85

      Pages: 4645-4647

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Relaxation and Diffusion of Photoexcited Carriers in ZnO Epitaxial Thin Films2004

    • Author(s)
      J.Takeda, K.Takagi, T.Okabe, H.J Ko, T.Yao
    • Journal Title

      phys.stat.sol.(c) 1

      Pages: 678-681

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Photoinduced Intramolecular Proton Transfer in 2-and 4-(2,4-Dinitrobenzyl)-pyridine2004

    • Author(s)
      J.Takeda, A.Nashiro, S.Kurita
    • Journal Title

      J.Lumin. 108

      Pages: 245-249

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Femtosecond Real-Time Pump-Probe Imaging Spectroscopy2004

    • Author(s)
      N.Furukawa, C.E.Mair, V.D.Kleiman, J.Takeda
    • Journal Title

      Appl.Phys.Lett. 85

      Pages: 4645-4647

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Direct Visualization of Transient Absorption by Real-Time Pump-Probe Imaging Spectroscopy2004

    • Author(s)
      N.Furukawa, C.E.Mair, V.D.Kleiman, J.Takeda
    • Journal Title

      Ultrafast Phenomena(Springer, Tokyo) XIV(印刷中)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Real-Time Capturing of the Nuclear Wave-Packet Shape in the Self-Trapped Excitons2003

    • Author(s)
      T.Matsuoka, J.Takeda, S.Kurita, T.Suemoto
    • Journal Title

      Phys.Rev.Lett. 91

      Pages: 247402:1-247402:4

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Photoinduced Magnetic Phase Transition in an Organic Radical 1,3,5-Trithia-2,4,6-Triazapentalenyl at Room Temperature2003

    • Author(s)
      J.Takeda, M.Imae, O.Hanado, S.Kurita, M.Furuya, K.Ohno, T.Kodaira
    • Journal Title

      Chem.Phys.Lett. 378

      Pages: 456-462

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Band Structure Calculation of TTTA Crystal2003

    • Author(s)
      M.Furuya, K.Ohno, T.Morisato, Y.Kawazoe, J.Takeda
    • Journal Title

      Trans.Mater.Res.Soc.Jpn. 28

      Pages: 911-914

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Photoinduced Diamagnetic to Paramagnetic Phase Transition in An Organic Radical Crystal Studied by Microscopic IR Measurements

    • Author(s)
      S.Oguri, O.Hanado, J.Takeda, M.Furuya, K.Ohno, S.Inoue, T.Kodaira
    • Journal Title

      J.Lumin. (印刷中)

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Direct Visualization of Transient Absorption by Real-Time Pump-Prove Imaging Spectroscopy

    • Author(s)
      N.Furukawa, C.E.Mair, V.D.Kleiman, J.Takeda
    • Journal Title

      Ultrafast Phenomena XIV, (Springer, Tokyo, 2004) (印刷中)

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Photoinduced Diamagnetic to Paramagnetic Phase Transition in An Organic Radical Crystal Studied by Microscopic IR Measurements

    • Author(s)
      S.Oguri, O.Hanado, J.Takeda, M.Furuya, K.Ohno, S.Inoue, T.Kodaira
    • Journal Title

      J.Lumin. (印刷中)

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

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Published: 2006-07-11  

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