Core level photoemission study of the growth of platinum on palladium (111)

We present a core level photoemission spectroscopy study, using synchrotron radiation of the first stages of PtPd(111) growth. Up to one monolayer (ML) of Pt interdiffusion leads to a surface alloy formed over the first two layers. Between 1 and 2 ML the system demixes, giving rise to a pure Pt overlayer, for coverages > ML. The role of the interface in the surface alloy formation is discussed.