J. Phys. IV France 07 (1997) C1-493-C1-494
Amorphous Oxide Films of the Bi2O3-Fe2O3-PbTiO3 System Coexisting Ferromagnetism and Ferroelectricity Prepared by Gel-CoatingT. Fujii1, T. Wada1, Y. Tokunaga1, K. Kawahito1, M. Inoue1, A. Kajima2, B. Jeyadevan3 and T. Tohji3
1 Department of Electrical and Electronic Engineering, Toyohashi University of Technology, 1-1 Hibariga-oka, Tempaku-cho, Toyohashi 441, Japan
2 Department of Electrical Engineering, Kitakyushu National College of Technology, 5-20-1, Shii, Kokura-Minami-ku, Kitakyushu 803, Japan
3 Department of Resources Engineering, Faculty of Engineering, Tohoku University, Aoba, Aramaki, Aoba-ku, Sendai 980-77, Japan
Magnetic and dielectric properties of films with the ternary oxide system Bi2O3-Fe2O3-PbTiO3 prepared by coating gel-solutions synthesized by the glycol-gel process on either glass plates or low resistivity Si-wafers were investigated. It was found that films with the Fe2O3-molar concentration around 70% exhibit ferromagnetic as well as ferroelectric behaviors simultaneously above room temperature retaining amorphous state from x-ray diffraction even after annealed at 700°C in air. The microstructure of the films was examined by EXAFS and was confirmed to be in a strongly disordered state. These pronounced properties are supposed to arise from a sort of excessively frustrated spin glasses.
© EDP Sciences 1997