Recent experiment discovered an interesting reversible intermixing process involving the exchange of the Ge atom in an adsorbed SiGe dimer with a substrate Si atom on the Si(001) surface. First-principles total energy calculations were used to study the atomistic mechanisms of diffusion and intermixing in this system. The calculations suggested that intermixing was triggered by the diffusion of the ad-dimer on the surface. The energy barriers for the diffusion and intermixing events obtained from the calculations were in good agreement with experiment.

Mixed SiGe Ad-Dimer on Si(001) - Diffusion Triggers Intermixing. Z.Y.Lu, C.Z.Wang, K.M.Ho: Surface Science, 2002, 506[3], L282-6