Photoinduced Magnetization with a High Curie Temperature and a Large Coercive Field in a Co-W Bimetallic Assembly

Authors

  • Noriaki Ozaki,

    1. Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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  • Hiroko Tokoro,

    1. Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
    2. NEXT, JSPS, 8 Ichibancho, Chiyoda-ku, Tokyo 102-8472, Japan
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  • Yoshiho Hamada,

    1. Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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  • Asuka Namai,

    1. Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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  • Tomoyuki Matsuda,

    1. Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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  • Souhei Kaneko,

    1. Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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  • Shin-ichi Ohkoshi

    Corresponding author
    1. Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
    2. CREST, JST, K's Gobancho, 7 Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan
    • Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
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Abstract

The crystal structure, magnetic properties, and temperature- and photoinduced phase transition of [{CoII(4-methylpyridine)(pyrimidine)}2{CoII(H2O)2}{WV(CN)8}2]·4H2O are described. In this compound, a temperature-induced phase transition from the CoII (S = 3/2)-NC-WV(S = 1/2) [high-temperature (HT)] phase to the CoIII(S = 0)-NC-WIV(S = 0) [low temperature (LT)] phase is observed due to a charge-transfer-induced spin transition. When the LT phase is irradiated with 785 nm light, ferromagnetism with a high Curie temperature (TC) of 48 K and a gigantic magnetic coercive field (Hc) of 27 000 Oe are observed. These TC and Hc values are the highest in photoinduced magnetization systems. The LT phase is optically converted to the photoinduced phase, which has a similar valence state as the HT phase due to the optically induced charge-transfer-induced spin transition.

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