Ohkoshi Shin-ichi, Ikeda Satoru, Hozumi Toshiya, Kashiwagi Toshinori, Hashimoto Kazuhito
Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
J Am Chem Soc. 2006 Apr 26;128(16):5320-1. doi: 10.1021/ja060510e.
A three-dimensional magnetic material {CoII(pyrimidine)(H2O)}2{CoII(H2O)2}{WV(CN)8}22. 2H2O is prepared. This compound exhibits a charge-transfer-induced spin transition with a large thermal hysteresis loop of 90 K. Irradiating with light causes the low-temperature phase to exhibit a spontaneous magnetization with a Curie temperature of 40 K and a magnetic hysteresis loop with a coercive field of 12 000 G, which is the highest value reported for a photomagnet. The observed photoinduced magnetization is due to the charge-transfer phase transition from the {CoIIhs(S = 3/2)}{CoIIIls(S = 0)}2-NC-{WIV(S = 0)}2 phase to the {CoIIhs(S = 3/2)}3-NC-{WV(S = 1/2)}2 phase by the irradiation.
制备了一种三维磁性材料{CoII(嘧啶)(H2O)}2{CoII(H2O)2}{WV(CN)8}22·2H2O。该化合物表现出电荷转移诱导的自旋转变，具有90 K的大热滞回线。用光照射会使低温相表现出自发磁化，居里温度为40 K，磁滞回线的矫顽场为12000 G，这是光磁体报道的最高值。观察到的光致磁化是由于通过照射，电荷转移相变从{CoIIhs(S = 3/2)}{CoIIIls(S = 0)}2-NC-{WIV(S = 0)}2相转变为{CoIIhs(S = 3/2)}3-NC-{WV(S = 1/2)}2相。
