Effects of sintering temperature on the microstructure and dielectric properties of BaZr0.2Ti0.8O3 ceramics

BaZr0.2Ti0.8O3 (short as BZT20) ceramics were prepared by a mixed-oxide method using a high-energy planetary ball mill and the effect of sintering temperature (Ts) on their microstructure and dielectric properties was firstly investigated. A cubic perovskite structure free from any secondary peaks was observed for all sintered samples with ~95% theoretical density. The Curie temperature for all sintered samples varied near room temperature along with a change in the degree of diffuse phase transition. With the increase in Ts, the average grain size increased from 25 μm to 70 μm, and the dielectric properties and tangent loss improved. The BZT20 ceramics sintered at 1350 °C exhibited permittivity of 20,048 and tangent loss of 0.01. The influence of 90° and 180° domains on dielectric behavior of BZT20 ceramics was also investigated.