Variation in electronic and optical responses due to phase transformation of SrZrO3 from cubic to orthorhombic under high pressure: a computational insight

In this paper, phase transition in SrZrO3 under high pressure has been investigated computationally using first principles calculation with ultra-soft pseudo-potential and generalized gradient approximation suggested by Perdew, Burke, and Ernzerhof correlation functional. The point where the enthalpy vs pressure curves of cubic and orthorhombic phases coincide is observed for the evaluation of phase transition pressure. The phase transition from cubic to orthorhombic has been observed at 72.0 GPa pressure. At phase transition, the electronic band gap, total density of states, lattice parameter, volume and optical properties of SrZrO3 are explored. The band gap as well as the lattice parameter and volume reduce during phase transformation from cubic to orthorhombic. The band gap values at 67.0 GPa for cubic and orthorhombic phases are simultaneously 3.418 eV and 4.117 eV whereas at final pressure of 74.0 GPa, these values are 3.368 eV and 4.108 eV, respectively. The calculated and reported values of refractive index, dielectric function and absorption spectra are comparable. The calculated values of static refractive index are 2.1 and 2.2 for cubic and orthorhombic SrZrO3, respectively.