The perovskite materials are of considerable technological importance, particularly with regard to physical properties such as pyro and piezoelectricity , dielectric susceptibility, linear and nonlinear optic effects. Many of these properties are gross effects, varying enormously from one perovskite to another and differences in crystal structures are hardly apparent . Effects of the impending transition are evident in some of the crystal properties at temperatures at least a few degrees away from
Structure of barium titanate:- Barium titanate is chemical compound with formula (BaTiO3) ,has perovskite structure (a group of crystalline material take it name from natural mineral perovskite (CaTiO3) with typical formula ABO3.[35] In barium titanate, (Ba:A) ion has large size (r=1.35 A), it located at the corner of unit cell and it is encompassed by (12) oxygen ion, oxygen are bound to both cation and it located at the center cubic face. While (Ti:B) are small in