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

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

doi:10.1021/ja060510e

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

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

Authors

Shin-ichi Ohkoshi¹, Satoru Ikeda, Toshiya Hozumi, Toshinori Kashiwagi, Kazuhito Hashimoto

Affiliation

¹ Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan. ohkoshi@light.t.u-tokyo.ac.jp

PMID: 16620085
DOI: 10.1021/ja060510e

Abstract

A three-dimensional magnetic material [{CoII(pyrimidine)(H2O)}2{CoII(H2O)2}{WV(CN)8}2](pyrimidine)2. 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.