Dielectric Behavior of Perovskite Barium Titanate and Barium Strontium Titanate Ceramics

Narendra Singh Rawat; Manisha Chawla; Seema Rawat; M. Fahim

Volume : IV, Issue : III, March - 2015

Dielectric Behavior of Perovskite Barium Titanate and Barium Strontium Titanate Ceramics

Narendra Singh Rawat, Manisha Chawla, Seema Rawat, M. Fahim

Abstract :

Stoichiometric compositions [(Ba+Sr):Ti =1:1] of barium strontium titanate (Ba1–xSrxTiO3) (where molar concentration x = 0, 0.2, 0.3, 0.4, 0.5 and 1.0) powders were prepared using a sol– gel technique via acetate method. The as–fired amorphous powders were annealed at 850oC to form nanocrystalline powders. These powders were then cold–pressed to make pellets which were then sintered at 1300oC to form dense ceramics. These ceramic pellets were electroded using conductive silver paste and characterized for their frequency and temperature dependent dielectric behavior in order to investigate the effect of strontium concentration on the dielectric constant of barium titanate (BaTiO3). It was observed that with increasing strontium concentration the ferroelectric to paraelectric phase–transition temperature (Tc) shifted to lower temperatures and dielectric constant increased substantially. With a very small addition of Sr (Ba0.8Sr0.2TiO3), a high dielectric constant and a low dielectric loss (