Effect of Bi2O3 Additive on the Microstructure and Dielectric Properties of BaTiO3-Based Ceramics Sintered at Lower Temperature

High performance X8R dielectric ceramics were prepared by doping Bi2O3 to BaTiO3-based ceramics. The effect of small amounts (<= 1.2 mol%) of Bi2O3 additive on the microstructure and dielectric properties of BaTiO3-based ceramics have been investigated. The Bi2O3, acting as a sintering additive, can effectively lower the sintering temperature of BaTiO3-based ceramics from 1300 to 1130 degrees C. The bulk density of BaTiO3-based ceramics increased and reached the maximum value with increasing Bi2O3 content. The dielectric constant increased with increasing Bi2O3 until it reached the maximum value with 0.8 mol% Bi2O3 additive, and the dielectric loss decreased with increasing Bi2O3 content. Optimal dielectric properties of epsilon=2470, tan delta=0.011 and Delta epsilon/epsilon(25)<=+/- 9% (-55-150 degrees C) were obtained for the BaTiO3-based ceramics doped with 0.8 mol% Bi2O3 sintered at 1130 degrees C for 6 h.