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.