Influence of Au reconstruction on growth of Fe on Au 100/

We have studied the initial stages of iron growth on Au 001. using in-situ UHV STM. The reconstructed 28=5. Au 001.surface of thin films grown on cleaved MgO 001.single crystals was used as a substrate for the Fe growth in a sub-monolayer range. For Fe coverages below 0.4 ML, the Fe growth is coupled to the Au reconstruction features. The reconstruction determines the shape and dimensions of Fe islands. An enhanced diffusion along the reconstruction ridges determines the coalescence of the Fe islands. For an increasing coverage, the growth becomes influenced by a segregation of Au to the surface. The segregation is closely connected with the vanishing of the Au reconstruction. The Au top monolayer promotes the layer-by-layer growth of Fe. q1999 Elsevier Science B.V. All rights reserved.