Mechanical and thermodynamic properties of ZrO2 under high-pressure phase transition: A first-principles study

The mechanical and thermodynamic properties of ZrO2 depending on pressure (0-20 GPa) were discussed firstly during the second-order phase transition (P21/c → Pbca → Pnma). Specifically, Young's modulus (E) and Debye temperature (Θ) were found to increase monotonously in the procedure. The three structures of ZrO2 were proved to be mechanical stability under the corresponding pressure range. Furthermore, the related phase transition pressures (9.09 GPa and 12.68 GPa) of ZrO2 were obtained by the enthalpy calculation based on the Birch-Murnaghan equation.