Adsorption of sulfur on Ag(100)

We have used scanning tunneling microscopy and density Functional theory to investigate the structures formed by sulfur on Ag(100). As indicated by previous low-energy electron diffraction studies, the main phases have unit cells of p(2 x 2) and (root 17 x root 17)R14 degrees. We show that the latter is a reconstruction. The favored structural model is one in which 5 Ag atoms are missing from the (100) surface plane per unit cell. The ejected Ag atoms combine with sulfur to form islands of the reconstructed phase on the terraces. The (root 17 x root 17)R14 degrees phase coexists with the p(2 x 2), at sulfur coverages slightly above 0.25 monolayers. In addition, chain-like structures are observed in SIM, both at room temperature (where they are dynamic) and below (where they are not). These results are compared with relevant literature for copper surfaces. (C) 2010 Elsevier B.V. All rights reserved.