Influence of Bi2O3 doping on the microstructure and dielectric properties of barium strontium titanate ferroelectric ceramics

BaxSr1-xTiO3[(BSTO), 0 <= x <= 1] is a solid solution ferroelectric material exhibiting a large dielectric constant non-linear change with an applied dc electric field. Pure BSTO can not satisfy the requirements of phase shifter due to its high dielectric constants and losses. it has been shown that the dielectric constants and losses of barium strontium titanate can be reduced by doping certain oxides. In this paper, we present systematic studies of the effect of Bi2O3 doping on BSTO bulk ceramics. The results showed that: (1) By adding Bi2O3 into BSTO bulk ceramics, Bi3+ substitute for Ba2+ cation sites at A position of ABO(3) perovskite structure to form homogeneous solid solution; (2) With the increase of Bi2O3-doping content, ferroelectric-paraelectric transition peaks become broadened, the maximum permittivity value decreases and dispersion phase transition effect is enhanced; (3) Proper quantity of Bi2O3 could reduce the grain size and dielectric constants of BSTO ceramics significantly.