Electronic and elastic properties of yttrium gallium garnet under pressure from ab initio studies

In this paper, we present an ab initio study within the framework of density functional theory employing the generalized gradient approximation applied to the study of the structural, elastic, and electronic properties of yttrium gallium garnet, Y3Ga5O12, under hydrostatic pressure. The calculated structural ground state properties are in good agreement with the available experimental data. Pressure dependence of the elastic constants and the mechanical stability are analysed up to 90 GPa, showing that the garnet is mechanically unstable above 84 GPa. We also present the electronic band structure calculations which show that upon compression the fundamental direct gap first increases up to 63 GPa and later monotonically decreases under pressure.