Electronic and optical properties of spinel Zn₂TiO₄ under pressure effect: ab initio study

Abstract

We performed density functional theory (DFT) studies of the lattice parameters, electronic band structure, and optical constants under pressure up to 20 GPa in order to obtain insight into the electronic and optical properties of spinel Zn₂TiO₄. The results indicate that the structural parameters such as lattice parameters and cell volume show inverse relation to the pressure and shows smooth decreasing behavior from 0 to 20 GPa. Meanwhile, the pressure dependence of the electronic band structure, density of states and partial density of states of spinel Zn₂TiO₄ up to 20 GPa were presented. From the detailed analysis of the electrical properties, it is concluded that external pressure might be the key reason to enhance band gap. Moreover, the evolution of the dielectric function, absorption coefficient (α(ω)), reflectivity (R(ω)), and the real part of the refractive index (n(ω)) at high pressure are also presented. According to our work, we found that the optical properties of spinel Zn₂TiO₄ undergo a blue shift with increasing pressure.

Graphical abstract