Investigation of pressure effects on melting temperature and shear modulus of B1-LiF

Abstract

The pressure effects on melting temperature and shear modulus of the B1 phase of LiF are investigated based on a semi-empirical approach. We derived analytical expressions of these quantities as functions of pressure. Numerical calculations are performed for LiF up to pressure of 100 GPa. Our work reveals that the melting curve derived from the Simon-Glatzel equation shows a high gradient at pressure below 30 GPa and rather quickly flattens with the increasing of pressure in accord with experiments, much more precise than the calculations based on the Lindemann melting criterion and the power-law of Grüneisen parameter. Meanwhile, the pressure-dependent shear modulus derived from Burakovsky’s model and the power-law of Grüneisen parameter shows a good agreement with ab initio calculations. Our results provide a further supplement to the database of high-pressure melting temperature and shear modulus of LiF. The present work could be used to verify as well as analyze the future high-pressure experiments.