Dielectrics composed of BaTiO3-rare earth oxide-MgO have been studied to de
sign a non-reducible low-loss dielectric material. Curie temperatures of di
electrics composed of BaTiO3-Gd2O3-MgO were lowered by Gd2O3,which provided
the dielectrics with low power loss. It was found that the addition of BaZ
rO3 to BaTiO3-Gd2O3-MgO decreased the capacitance change with temperature.
Gd2O3 diffused easily into BaTiO3, but, it could nor easily diffuse into Ba
TiO3 to which BaZrO3 had been added. It was considered that BaZrO3 prevente
d the Gd2O3 diffusion into BaTiO3, resulting the remains of ferroelectricit
y and reduced capacitance change. Thus non-reducible and low power loss X7R
dielectric ceramics were developed.