Temperature Dependent Dielectric Properties of Ba-La-Sm-Bi-Ti-O Ceramic System

The temperature dependent dielectric properties of some of the compounds in Ba-La-Sm-Bi-Ti-O ceramic system have been studied for developing temperature stable high dielectric constant ceramics. Two series, Ba-4(La0.5-zSm0.5Biz)(9.33)Ti18O54, and Ba-4(La0.3-zSm0.7Biz)(9.33)Ti18O54, where z = 0.0, 0.1, 0.2, have been synthesized by conventional mixed oxide route and characterized. The study revealed that the substitution of rare earths (Sm, La) and Bi has been found effective in achieving high dielectric constant along with stabilizing the variation in dielectric constant with temperature. Ba-4(La0.5-zSm0.5Biz)(9.33)Ti18O54 with z = 0.2 and Ba-4(La0.3-zSm0.7Biz)(9.33)Ti18O54 with z = 0.1 posses high dielectric constant with small temperature variation of the resonant frequency (+/- 5 ppm/degrees C). These could be dielectric materials for practical applications.