Effect of Sr-doping on the band structure of BaTiO3 through density functional theoretical calculations

Ba1-xSrxTiO3 has been one of the most widely studied solid solution among the perovskite based oxides useful in many device applications. Using first principle calculations in the framework of density functional theory, we studied the effect of strontium doping in BaTiO3 by computing the electronic band structure and density of states (DOS) using the plane wave pseudo potential formalism. The generalized gradient approximation (GGA) with standard Perdew-Bruke-Ernzerhof (PBE) exchange-correlation functional and norm conserving potential and local density approximation (LDA) with Caperlay-Alder Perdew-Zunger (CA-PZ) and ultra-soft pseudo potential was used. The optical band structure of Ba1-xSrxTiO3 for (x = 0.0, 0.25, 0.50) shows the indirect band gap at M to G points in the Brillion zone decreasing with Sr concentration.