Structure and dielectric characteristics of Ca(Fe1/2Ta1/2)O3 complex perovskite ceramics

Ca(Fe1/2Ta1/2)O3 complex perovskite ceramics have been prepared and characterized in the crystal structure and microstructures, and the dielectric characteristics have been evaluated over a broad temperature and frequency range. There are two dielectric relaxations in low and high temperature ranges, respectively. Differing from the situation for Ba(Fe1/2Ta1/2)O3, Sr(Fe1/2Ta1/2)O3 and Ba(Fe1/2Nb1/2)O3, O2-annealing has little effect on the dielectric properties of Ca(Fe1/2Ta1/2)O3, and the much lower dielectric constant and low loss are ascribed to the low concentration of Fe2+ according to the XPS measurements. The microwave dielectric properties (at 5.38 GHz) for Ca(Fe1/2Ta1/2)O3 ceramics are obtained as: ɛr = 30.7, Qf = 3070 GHz.