Insight into the pressure effect on the structural stability and physical properties of cubic sesquioxides X2O3 (X= Sc, Y and In)

Abstract

The structural stability, elastic properties and elastic anisotropy of cubic sesquioxides Sc2O3, Y2O3 and In2O3 under pressure are systematically investigated using the first-principles calculations. For three materials, the pressure dependent behaviors of the structural stability and mechanical properties are investigated from 0 to 15 GPa. The formation enthalpy, volume change, phonon frequencies and mechanical stability confirm that cubic Sc2O3, Y2O3 and In2O3 exhibit the structural stability at ground state and high pressure. The elastic constants, elastic moduli and anisotropy increase with the increasing pressure. The pressure promotes that the ductile ability and the anisotropic degree increase with the increasing pressure.