First principle study of the effect of pressure on the optical properties of cubic-LaAlO3 compound

In this paper, some optical properties of cubic-LaAlO3 have been calculated at various pressures. These properties are dielectric function, energy loss function, optical conductivity and refractive index. In our calculation we have used density function theory (DFT) and generalized gradient approximation (GGA). The results showed that with increasing pressure the dielectric function and static refraction index are decreased at low energies. The analysis of energy loss function in terms of pressure confirmed that below 41.1 GPa, the plasmon energy is increased and then decreased. Furthermore, with increasing pressure the optical band gap was increased and reached to 5.91 eV.