Ge deposition on Ag surfaces: Dependence of the adsorption characteristicson the surface orientation

Using the ab initio full-potential linear muffin-tin orbital approach we ha ve studied the characteristics of Ge adsorption on three different Ag surfa ces. We have analyzed the surface-orientation-dependent characteristics of the Ge adsorption, focusing our attention on comparison between adatom and substitutional adsorption. We find that whereas on the (111) surface substi tutional adsorption is preferential, on the (100) and (110) ones the two ad sorption modes have similar energetics. Analysis of the adsorption-induced modifications of the electronic structure of both the substrate and the ads orbate supports the thesis that at small coverage, Ge deposition on the Ag surfaces is to a large extent determined by laws characteristic for metal o n metal adsorption.