The effect of pressure variation on the elasticity and thermodynamic properties of CaLiF3 for low birefringent lens materials

Abstract

In this study, the Full-Potential Linearized Augmented Plane Wave (FP-LAPW) method is employed to calculate the effect of pressure variation (0–50 GPa) on the electronic structure, elastic parameters, mechanical durability, and thermodynamic aspects of calcium based CaLiF3 in combination with the Quasi-harmonic Debye model where the phonon effects are considered. A prominent decrease in the value of the lattice constant and the bond lengths is observed with an increase in pressure. The significant influence of pressure on a wide range of elastic parameters and their related mechanical properties has been discussed in detail to utilize this material in low birefringence lens fabrication technology. The transition from brittle to ductile behavior is also observed with an increase in pressure. Moreover, a successful prediction of the important thermodynamic aspects, such as the volume expansion coefficient (α), Debye temperature (θD), and heat capacities (Cp and Cv), is also done in wide pressure and temperature ranges.