DENSITY FUNCTIONAL THEORY CALCULATION OF BAND STRUCTURE OF PEROVSKITE-TYPE MATERIAL BARIUM TITANATE (BaTiO3)

Abstract

Perovskite-type structure, barium titanate (BaTiO₃) has a great potential in microelectronic industry especially, in capacitors and energy storage devices due to the high dielectric constant and wide band gaps around 3.2 eV. Many theoretical investigations on the band structure of BaTiO₃ by using density functional theory (DFT) calculation has been done with the different approximations but the accuracy of the calculation was questionable. The most fundamental local density approximation (LDA) methods were reported to be heavily underestimated the band gap of BaTiO₃ by 50% between the experimental values. In this study, the hybrid functional B3LYP was used in order to overcome the “band gap problem” in DFT calculation. The first-principle calculations based on DFT method were performed using Material Studio, CASTEP then the results were compared with the previous experiment data.