STRUCTURAL AND DIELECTRIC PROPERTIES OF MODIFIED BARIUM TITANATE CERAMICS

Abstract

The solid state reaction of BaCO3, CaCO3 and Ti02 to form (Bao.9Cao.1) TiO3 at different temperatures and heating rates was investigated. Here we study the structural and dielectric properties of calcium modified barium titanate. The main aim of this work is to synthesize, characterize and the dielectric properties of the calcium modified barium titanate ceramics. In the synthesis of BaTiO3 perovskites, there are six steps: weighing of the chemicals, powder mixing, grinding, calcination, pelletizing and sintering. The particle size of BT ceramics was found to be of the order of 0.76 μm. As we increase the Ca contain in BT ceramics, particle size were found to be of the of 0.098 μm. The Diffusivity of the BT Samples is found to increase from 1 to 2 with heating temperature, indicating that the second order diffuse phase transition is developing at high heat treated samples. Diffraction peaks can be indexed both BCT and BT, indicating that a pure phase BCT was synthesized and no structural transition. Coarse grain samples preserve the tetragonal pervoskite structure, while the fine grain samples consist of multiphases with the cubic pervoskite structure.