Study of pressure variation effect on structural, opto-electronic, elastic, mechanical, and thermodynamic properties of SrLiF3

摘要

The structural, electronic, elastic, optical and thermodynamic properties of cubic fluoroperovskite SrLiF3 at ambient and high-pressure are investigated by using first-principles total energy calculations within the framework of Generalized Gradient Approximation (GGA), combined with Quasi-harmonic Debye model in which the phonon effects are considered. The pressure effects are determined in the range of 0-50 GPa, in which cubic stability of SrLiF3 fluoroperovskite remains valid. The computed lattice parameters agree well with experimental and previous theoretical results. Decrease in lattice constant and bonds length is observed with the increase in pressure from 0 to 50 GPa. The effect of increase in pressure on electronic band structure calculations with GGA and GGA plus Tran-Blaha modified Becke-Johnson (TB-mBJ) potential reveals a predominant characteristic associated with widening of bandgap. The influence of pressure on elastic constants and their related mechanical parameters have been discussed in detail. All the calculated optical properties such as the complex dielectric function epsilon(omega), optical conductivity sigma(omega), energy loss function L(omega), absorption coefficient alpha(w), refractive index n (omega), reflectivity R (omega), and effective number of electrons n(eff), via sum rules shift towards the higher energies under the application of pressure. Moreover, important thermodynamic properties heat capacities (C-p and C-v), volume expansion coefficient (alpha), and Debye temperature (theta(D)) are predicted successfully in the wide temperature and pressure ranges.