SELF-SURFACTANT EFFECT ON FE AU(100) - PLACE EXCHANGE PLUS AU SELF-DIFFUSION/

In this paper, we report on the submonolayer growth of Fe on Au(100), a system where a monolayer of the substrate floats at the external sur face during growth facilitating the layer-by-layer growth of the Fe fi lm. STM and STS demonstrate that this self-surfactant action results f rom a combination of several processes: fast place exchange between Fe and the Au atoms of the topmost surface layer, anisotropic diffusion of the Au atoms ejected due to the local lifting of the surface recons truction, and preferential nucleation on the isolated Fe atoms embedde d within the surface. The Au atoms diffuse over the surface in a way a lmost identical to the homoepitaxial growth of Au on Au(100). As a res ult, stable, reconstructed islands composed of Au atoms are formed and end up burying the deposited Fe. (C) 1998 Elsevier Science B.V. All r ights reserved.