不規則系酸化物における光学的2次非線形性と磁気秩序(第59回日本セラミックス協会学術賞受賞研究総説)

概要

論文の詳細を見る
Recent research activities of the author's group concerning second-order optical nonlinearity induced in amorphous oxides and magnetic order in a disordered crystalline lattice are described. For the second-order optical nonlinearity, an attention is paid to second-harmonic generation (SHG) in thermally or optically poled tellurite glasses. Some tellurite glasses which exhibit interesting properties such as very stable second-order nonlinearity and large second-order nonlinear susceptibility are presented. The former is realized in ZnO-TeO_2 glass, and the latter is attained for Na^+-doped WO_3-TeO_2 glass. Also, the mechanism for SHG in optically poled Nb_2O_5-TeO_2 glasses doped with vanadium ions is argued. A model including two-step absorption at a wavelength of 532nm and the presence of photo-induced electrons and positive holes trapped at localized states is proposed. On the other hand, magnetic and magnetooptical properties of disordered ZnFe_2O_4 thin film prepared by a sputtering method are reported as an interesting example of magnetic order in a disordered lattice. The resultant disordered thin film shows high magnetization even at room temperature and a spin-freezing temperature higher than room temperature. The temperature dependence of magnetization under the conditions of field cooling and zero-field cooling, the dependence of spin-freezing temperature on frequency of ac magnetic field, and temperature variation of ac nonlinear susceptibility suggest that the spin-freezing or magnetic transition of the disordered ZnFe_2O_4 thin film is explainable in terms of the superparamagnetism with strong intercluster interactions. It is also demonstrated that large Faraday effect is observed in a short wavelength range for the disordered ZnFe_2O_4 thin film.
社団法人日本セラミックス協会の論文
2005-08-01

不規則系酸化物における光学的2次非線形性と磁気秩序(第59回日本セラミックス協会学術賞受賞研究総説)

スポンサーリンク

概要

著者

関連論文

スポンサーリンク