A van der Waals three body force rigid shell model (VTRSM) developed earlier for NaCl and CsCl structure was expanded by us for zinc blende structure (ZBS). This model includes the effect of three body interactions and van der Waals interactions in the rigid shell model where short-range interactions were considered up to the second neighbor. Our model thus developed was applied to study the phonon dispersion curves, Debye temperature variation, two phonon Raman/IR spectra, and anharmonic elastic properties of ZnS. Our results are in good agreement with the measured data wherever available.

Abstract:We report the results of a theoretical study on phonon dispersion curves (PDCs) along the three principal symmetry directions, Debye temperature variation, combined density of states (CDS) curves, two-phonon Raman/IR peaks, and anharmonic elastic properties (third order elastic constants and their pressure derivatives) of ZnTe. This new van der Waals three-body force rigid shell model (VTRSM) incorporates the effect of van der Waals interactions and three-body interactions into the rigid shell model of zinc blende structure, where the short range interactions are operative up to the second neighbors. Our results are in good agreement with the available measured data for zinc telluride. It is concluded that this VTRSM will be equally applicable to study the above properties of other zinc blende structure solids.