Structural, elastic and mechanical properties of orthorhombic SrHfO3 under pressure from first-principles calculations

Structural, elastic and mechanical properties of orthorhombic SrHfO3 under pressure have been investigated using the plane-wave ultrasoft pseudopotential technique based on the first-principles density functional theory. The calculated equilibrium lattice parameters and elastic constants of orthorhombic SrHfO3 at zero pressure are in good agreement with the available experimental and calculational values. The lattice parameters, total enthalpy, elastic constants and mechanical stability of orthorhombic SrHfO3 as a function of pressure were studied. With the increasing pressure, the lattice parameters and volume of orthorhombic SrHfO3 decrease whereas the total enthalpy increases. Orthorhombic SrHfO3 is mechanically stable with low pressure (<52.9 GPa) whereas that is mechanically instable with high pressure (>52.9 GPa). The bulk modulus, shear modulus, Young's modulus and mechanical anisotropy of orthorhombic SrHfO3 as a function of pressure were analyzed. It is found that orthorhombic SrHfO3 under pressure has larger bulk modulus, better ductility and less mechanical anisotropy than orthorhombic SrHfO3 at 0 GPa.