The third-order elastic constants of potassium chloride, sodium chloride and lithium fluoride

Abstract

The complete set of third-order elastic constants of potassium chloride, sodium chloride and lithium fluoride have been measured at room temperature under conditions which eliminate the possibility that plastic deformation occurred during the experiments. A partial check on these values, provided by the pressure derivatives of the elastic constants, shows satisfactory agreement with experiment for potassium chloride and sodium chloride but shows some discrepancies for lithium fluoride With minor exceptions, the values agree with those predicted by Ghate using a Born-Mayer repulsive potential out to second-nearest neighbours