Sintering and Dielectric Properties of Hydrothermally Synthesized Cubic and Tetragonal BaTiO₃ Powders

Abstract

The sintering behavior of hydrothermally synthesized cubic and tetragonal BaTiO 3 powders was studied as a function of temperature. In addition, the dielectric properties of the sintered samples were examined from room temperature to 200°C at a frequency of 1 kHz. The influence of powder characteristics and sintering temperature on the microstructure development and dielectric properties were investigated. It was found that tetragonal powders showed limited grain growth and higher final density upon sintering, whereas the cubic powder exhibited abnormal grain growth and lower density. This was attributed to more disperse and homogeneous particles in the tetragonal powders with fewer defects, as compared to the cubic powder. Correlations between the microstructure and the dielectric properties were developed. As expected, samples with finer grain size and higher density exhibited higher dielectric constant and lower loss.