= 0.02,0.05,0.15,short for BSBT) ceramics were synthesized by the traditional solid state reaction method. Sintering was done at 1473 K for 2 h in air atmosphere. The structural
microstructure and dielectric properties of ceramics were investigated
in which a diffuse phase transition was exhibited in dielectric studies and a diffuse dielectric anomaly was observed in high temperature range. According
to the fitting results of Curie-Weiss law
BSBT ceramics exhibited a stronger phase transition for
x
=0.05. Besides
grain boundary resistivity of BSBT ceramics was characterized by an impedance analysis and activation energy and the activation energy for conduction calculated. Polaron theory indicated that the relaxation in BSBT ceramics at high temperatures was associated with the hopping ions caused by oxygen vacancies. And it is suggested that the diffuse dielectric anomaly for all samples was due to a competition between the dielectric relaxation behavior and the variation of the relaxation strength.