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

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 (3) over barm) to an orthorhombic structure (Cmcm), and subsequently to a tetragonal structure (I4/mcm). These transitions occur at pressures of 3.5 and 20 GPa, respectively. The calculated transition pressure from Cmcm to I4/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.