First-Principles Study of Pressure-Induced Structural Phase Transitions in BaZrO3

Abstract

Perovskite BaZrO₃ possesses higher phase stability from room temperature up to its melting point, yet pressure can induce phase transitions. However, detailed theoretical reports on pressure-induced transformations are scarce. We investigated the pressure-induced phase transition, elastic and electronic properties of BaZrO₃ under high pressure using first-principles calculations. The findings reveal that BaZrO₃ undergoes a series of structural transitions with increasing pressure, shifting from a cubic perovskite structure (\(Pm\bar {3}m\)) to an orthorhombic structure (Cmcm), and subsequently to a tetragonal structure (\(I4{\text{/}}mcm\)). These transitions occur at pressures of 3.5 and 20 GPa, respectively. The calculated transition pressure from Cmcm to \(I4{\text{/}}mcm\) structure is consistent well with experimental values, and the predicted Cmcm structure should be further testified by future experimental study. At zero pressure, the mechanical stability of perovskite BaZrO₃ is assessed through elastic constants. Additionally, all stable polymorphs of BaZrO₃ remain insulating nature under high hydrostatic pressure. This investigation provides insight into the complex pressure-induced phase transformations in BaZrO₃ and offers guidance for future experimental investigations and potential applications.