氰基桥联钴钨酸盐双金属组装体中具有高居里温度和大矫顽场的光致磁化

Photoinduced magnetization with a high curie temperature and a large coercive field in a cyano-bridged cobalt-tungstate bimetallic assembly.

作者信息

Ohkoshi Shin-ichi, Ikeda Satoru, Hozumi Toshiya, Kashiwagi Toshinori, Hashimoto Kazuhito

机构信息

Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.

出版信息

J Am Chem Soc. 2006 Apr 26;128(16):5320-1. doi: 10.1021/ja060510e.

DOI:10.1021/ja060510e

PMID:16620085

Abstract

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.

摘要

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。