Effects of sintering temperatures on microstructure and dielectric constant of Ba0.05SrxCa0.95-xTiO3 where (x=0, 0.475 and 0.95)

Abstract

Abstract Barium strontium calcium titanate is a candidate material for fabrication of electronic devices. It is generally accepted that microstructural control is a route to enhance dielectric constants of dielectric materials. This study aims at examining effects of sintering process on microstructure and dielectric constants of the Ba0.05Ca0.95TiO3, Ba0.05Sr0.475Ca0.475TiO3 and Ba0.05Sr0.95TiO3 samples. The Ba0.05Ca0.95TiO3, Ba0.05Sr0.475Ca0.475TiO3 and Ba0.05Sr0.95TiO3 powder was synthesized by solution combustion technique, uni-axially pressed and sintered at 1200, 1250, 1300, 1350 and 1400 °C, respectively. X-ray diffraction revealed a single phase powder with an average particle size smaller than 350 nanometers. Effects of the sintering temperature on density, shrinkage and grain sizes were evident: density, shrinkage and grain sizes increased with the sintering temperature. Grain sizes lower than 5 micrometers, density in the range between 55.32% and 95.7 % of theoretical density, and dielectric constant in the range between 25 and 163 at 1 MHz were observed. A relationship among grain sizes, density and dielectric constants were discussed.