Mechanical and optical properties of MgTa2O6 compounds: First principles study

Abstract

In this study, we have explored the electronic, optical, and mechanical properties of MgTa₂O₆ compounds in both tetragonal and orthorhombic phases using the first principles based on density functional theory (DFT) methods. Considering that GGA underestimates the band gap of materials, the HSE06 hybrid functional is performed to get a more accurate result for the band structure and optical property calculations. The calculations indicate that the tetragonal and orthorhombic phases exhibit different optical characteristics, showcasing their potential as exceptional materials for UV absorption. In addition, we have thoroughly investigated the elastic properties of MgTa₂O₆ for these two phases, including the bulk modulus, shear modulus, Young's modulus, and Poisson's ratio. The results indicate that the tetragonal phase has better volume deformation and shear deformation resistance, and the surface contours of Young's modulus for MgTa₂O₆ display anisotropy. And according to Pugh's criteria, the tetragonal phase has good ductile properties.