THE INITIAL-STAGES OF DEPOSITION OF AU AND AG ON CU(001) STUDIED BY LOW-ENERGY ION-SCATTERING

Using impact collision ion scattering spectroscopy, we have studied th e initial stage of the deposition of Au and Ag onto the Cu(001) surfac e. Our analysis provides evidence for surface alloying by the substitu tion of Cu with Au atoms in the surface, even at very low coverages at room temperature. However, the diffusion of Au atoms into the Cu subs trate was not observed at coverages below 0.25 ML. The growth of an he xagonal c(2 x 14)-Au layer on top of the first c(2 x 2) structure was found to promote the diffusion of Au atoms into the Cu substrate, dest roying the ordered arrangement of the c(2 x 2) structure. Ag was confi rmed to form a simple overlayer up to 1 ML without any diffusion of Ag atoms into the substrate. The growth mode of the Ag deposition was id entified to be of the Stranski-Krastanov type.