Pressure E ects on structural, electronic, elastic, and optical properties of cubic and tetragonal phases of BaZrO3

Abstract

A recent experimental study found the phase transition from cubic to tetragonal phase at 17.2 GPa in BaZrO3. In this paper, we investigate the structural, electronic, elastic, and optical properties of BaZrO3 in the cubic and tetragonal structures under pressure by using first-principle density-functional theory. The main results are summarized as follows: (1) An indirect band structure is displayed for both cubic and tetragonal phases. The band gap increases by ≈ 1 eV as a result of the phase transition. (2) The elastic constants Cij’s indicate that the cubic and tetragonal phases are mechanically stable. The easiest deformation mechanism in both phases is the shear along the (100) plane. (3) The real and imaginary parts of dielectric function for the cubic and tetragonal phases shift towards higher energies with pressure. Our results are in agreement with the available experimental and prior theoretical data.