Ab initiostudy of structural and thermal properties ofScAlO3perovskite

The pressure dependent structural properties of ${\mathrm{ScAlO}}_3$ perovskite have been determined using total energy calculations within the density functional theory framework. Based on the ab initio ground state parameters the Debye model was used to compute the phonon contribution to the total free energy. We have found that the ${\mathrm{ScAlO}}_3$ perovskite has orthorhombic structure at 0 K and ambient pressure. This structure is stable relative to the cubic perovskite structure up to pressures of ∼200 GPa and temperatures of ∼800 K. The present results support the experimentally observed analogy between ${\mathrm{ScAlO}}_3$ and ${\mathrm{MgSiO}}_3$ perovskites.