Ionic contribution to experimental gradient elastic tensors in III-V semiconductors

Previously published nuclear-acoustic-resonance determinations of the components $S_{11}$ of the fourth-rank tensor $S$ relating electric field gradients to elastic strain in III-V semiconductors are reinterpreted. Harrison and Phillips have used a particular bond-orbital deformation in getting good agreement between bond-orbital-model predictions and experimental values of the force constants $c_{11}-c_{12}$ in diamond-, zinc-blende-, and wurtzite-structure crystals. By using the Harrison and Phillips bond-deformation model, it is shown that experimental $S_{11}$ values are due only to ionic contributions. Estimates are given of the Sternheimer antishielding constants in these solids.