Prof. Yuichi Shimakawa, Advanced Solid State Chemistry, Institute for Chemical Research, Kyoto University, Japan

Title: Novel electronic and magnetic properties in transition-metal oxide ceramics

Abstract: Transition-metal oxide ceramics are widely used in current electronic devices, which include ferroelectrics, ferromagnets, conductors, and so on. The wide variety of such properties are given by various electronic and magnetic structures of the transition-metal oxides and are topics of interests in not only technological applications but also fundamental materials science. In this talk, intriguing electronic and magnetic properties in perovskite-structure oxides containing Fe. The examples include the newly discovered A-and-B-site-ordered quadruple perovskite CaCu3Fe2Re2O12, which shows ferrimagnetism with an unusually high magnetic transition temperature and large magnetization. More importantly, the electronic structure of CaCu₃Fe₂Re₂O₁₂ is half metallic, and the compound shows large magnetoresistance by conduction of spin-polarized electrons.