Development of Novel Phase Transition Mechanisms for Molecular Conductors by Applying Multiplicity of Electronic State Determinant Factors

2018 Fiscal Year Final Research Report

• Project/Area Number: 26288035
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Functional solid state chemistry
• Research Institution: Kyoto University
• Principal Investigator: Yamochi Hideki 京都大学, 理学研究科, 教授 (20182660)
• Research Collaborator: Otsuka Akihiro ; Nakano Yoshiaki ; Ishikawa Manabu ; Kitagawa Hiroshi ; Maesato Mitsuhiko ; Yoshida Yukihiro ; Uruichi Mikio ; Koshihara Shin-ya ; Onda Ken ; Okimoto Yoichi ; Tanaka Koichiro ; Saito Gunzi ; Hiramatsu Takaaki ; Shimizu Yasuhiro ; Ito Hiroshi ; Kishida Hideo ; Haruki Rie ; Kumai Reiji ; Adachi Shinichi ; Miller Dwayne, R. J. ; Khasanov Salavat, Salim'yanovich ; Konarev Dmitry, Valentinovich ; Lyubovskaya Rimma, N. ; Shao Xiangfeng ; Kushch Nataliya, D. ; Yagubskii Eduard, B.
• Project Period (FY): 2014-04-01 – 2019-03-31
• Keywords: 分子性固体 / 分子性導体 / 有機導体 / 強相関電子系 / 結晶工学 / 磁性

Outline of Final Research Achievements

This project aimed to develop new types of electronic phase transition phenomena for molecular crystals. As the main themes, (1) the chemical modulation of the ethylenedioxytetrathiafulvalene (EDO-TTF) salt showing the multi-instability of metallic state was performed to induce the different kind of photo-induced response comparing with the original material and (2) a peculiar charge-order melting, at which only the restricted parts in the periodic crystal structure show the homogenization of the molecular charge, was found in a multi-component charge-ordered material designed by our unique concept. Also, (3) new radical anion salts of fullerenes and macrocyclic compounds were prepared by employing strong reductants. As a result, the magnetic phase transition associated with the modulation of molecular charges was observed in a fullerene salt.

Free Research Field

合成有機物理化学

Academic Significance and Societal Importance of the Research Achievements

温度・圧力などの変化や光照射などの刺激に対して電子状態の変化を伴う応答(相転移)を起こす物質の研究は、電子材料開発に向けた基礎研究であり、同時に基礎科学そのものの重要課題である。新規物質の開拓を主たる手法とした本研究により、化学組成を僅かに変化させることによりパルス光照射に対する応答が異なる物質群が得られ、また、温度変化に対して結晶内での電子の分布様式が従来には見られなかった変化を起こす物質を得るなど、新規な現象を見出すことが出来た。これらの成果は物質中の電子の振舞いを理解しようとする基礎科学的な研究分野に新たな検討対象を与えた。