Local atomic structure of semiconductor alloys using pair distribution functions. II.

A method of calculating the pair distribution function in semiconductor alloys has been extended to the differential and the partial pair distribution functions, and applied to pseudobinaries of the form A_1-xBₓC with the zinc-blende structure. We have used a simple valence force model with bond-stretching and bond-bending forces. Results of calculations are presented for Ga0.5In0.5As. The differential pair distribution function provides a useful experimental way of determining the structural distortions in semiconductor alloys---specifically the mean nearest-neighbor and second-neighbor distances and widths can be obtained for chemically specific pairs of atoms.