Pressure dependence of elastic and dynamical properties of zinc-blende ZnS and ZnSe from first principle calculation

TL;DR

This study uses first-principles calculations to analyze how pressure influences the elastic and dynamical properties of zinc-blende ZnS and ZnSe, highlighting theoretical predictions and their comparison with experimental data.

Contribution

It provides detailed first-principles insights into pressure effects on elastic and phonon properties of ZnS and ZnSe, including pressure derivatives and mode Grüneisen parameters.

Findings

Calculated elastic constants are overestimated but align with recent theories.

Phonon spectra and dynamical effective charges vary with pressure.

Discrepancies with experiments are attributed to LDA and temperature effects.

Abstract

The density-functional theory (DFT) and density-functional perturbation theory (DFPT) are employed to study the pressure dependence of elastic and dynamical properties of zinc-blende ZnS and ZnSe. The calculated elastic constants and phonon spectra from 0 GPa to 15 GPa are compared with the available experimental data. Generally, our calculated values are overestimated with experimental data, but agree well with recent other theoretical values. The discrepancies with experimental data are due to the use of local density approximation (LDA) and the effect of temperature. In this work, in order to compare with experimental data, we calculated and discussed the pressure derivatives of elastic constants, the pressure dependence of dynamical effect charge, and mode Gr\"uneisen parameter at \Gamma.