ATOMIC-SCALE STRUCTURE OF IONIC AND SEMICONDUCTING SOLID-SOLUTIONS

Experimental studies of the atomic scale structure of ionic and semico nducting solid solutions have shown that the bond-length mismatch is p artially accommodated by microscopic lattice distortions and that the values of the nearest-neighbour bond lengths are intermediate between those of the corresponding pure compounds and the average Vegard value . Here we investigate theoretically the atomic scale structure of allo ys using a generalized Born-Mayer model in the ionic case and an ab-in itio pseudopotential approach for semiconductors. We also present resu lts for the atomic scale structure of semiconductor heterojunctions an d discuss how much interfacial and bulk strains can influence the elec tronic properties of the interface.