Dielectric Properties of Ba0.7Sr0.3TiO3 Ceramics with Different Grain Size

Abstract

Ba0.7Sr0.3TiO3 ceramics with different grain sizes were prepared by the sol–gel method. The temperature dependence of the dielectric properties of the ceramics was studied. There are two dielectric peaks, corresponding to the cubic–tetragonal(C–T) and tetragonal–orthorhombic(T–O) phase transitions, respectively. With the decrease of grain size, the Curie temperature decreases while the T–O transition temperature increases, and the two dielectric peaks become lower and broader and eventually disappear in the following sequence: T–O, C–T. The ferroelectric critical size and the grain size dependence of the dielectric constant are also discussed.