First-Principles Calculations of the Structural, Electronic and Optical Properties of BaZr_xTi_1−xO₃ (x=0, 0.25, 0.5, 0.75)

The pseudo-potential plane wave (PP-PW) method with the generalized gradient approximation (GGA) is used to calculate the structural, electronic and optical properties of cubic and tetragonal BaZr_xTi_1−xO₃(BZT) (x= 0, 0.25, 0.5, 0.75). The calculated structural parameters are found to be in good agreement with the experimental data. The energy band structure density of states (DOS) are obtained, which indicates that the Zr substitute can induce the band gap widening of BaTiO₃. Furthermore, their optical properties are also calculated and analyzed in detail. It is shown that the dielectric imaginary part of BZT decreases as x (Zr concentration) increases.