AG ON AU SI(111) - INTERFACIAL INTERACTIONS ON A SUBMICROMETER SCALE/

The interaction of Ag with a (root 3x root 3)R30 degrees-Au/Si(111) in terface containing Au microparticles is studied by means of photoelect ron spectromicroscopy with the goal being to understand the microscopi c aspects of the interface evolution. The distribution and the composi tion differences of the two phases are evaluated from the contrast in the Au, Ag, and Si maps and by analysis of the spatially resolved An 4 f, Si 2p, and Ag 3d photoelectron spectra. The surface processes contr olling locally the evolution of the bimetal Ag+Au/Si interface and the correlation between the Au chemical state and the reactivity of the p hases are revealed and discussed.