Self-diffusion studies were performed by using an isotopically controlled multi-layer crystalline GaSb structure. It was noted that stable isotopes existed for both Ga and Sb; thus permitting the simultaneous study of diffusion on each sub-lattice. The results showed that, near to the melting point, Ga diffused more rapidly than Sb by over 3 orders of magnitude. This surprisingly large difference in atomic mobility required a physical explanation that went beyond standard diffusion models. Upon combining the present data with related results for foreign-atom diffusion in GaSb, it was concluded that the unusually slow Sb diffusion in GaSb was due to reactions - between defects on the Ga and Sb sub-lattices - which suppressed the defects that were required for Sb diffusion.

Large Disparity between Gallium and Antimony Self-Diffusion in Gallium Antimonide. H.Bracht, S.P.Nicols, W.Walukiewicz, J.P.Silveira, F.Briones, E.E.Haller: Nature, 2000, 408[6808], 69-72