One monolayer of Ag deposited on Cu(111) showed two kinds of characteristic reconstruction, depending on the conditions of the preparation: the incommensurate moiré structure appeared for one monolayer prepared at 200K whereas a monolayer deposited at room temperature (or higher) exhibited a quasi-commensurate triangular structure. By performing high-resolution ARUPS measurements on the triangular structure, an opening of a gap in the Shockley state band was found, which was a signature of the super-lattice. On the other hand, no gap opening was observed on the moiré structure. In addition, it was shown that the Shockley state played an important role in the adsorption process of rare gas atoms on these surfaces. ARUPS experiments on adsorbed Xe on 0.6ML Ag/Cu(111) showed clearly that the Xe atoms favoured the adsorption on the Ag islands, before the Cu terraces were covered at higher Xe exposure.

Quantitative Analysis of the Surface Reconstruction Induced Band-Gap in the Shockley State on Monolayer Systems on Noble Metals. A.Bendounan, F.Forster, J.Ziroff, F.Schmitt, F.Reinert: Surface Science, 2006, 600[18], 3865-9