Angle resolved X-ray photoelectron spectroscopy study of Au deposited on Pt and Re surfaces

The growth of Au on Pt and Re sputtered and annealed surfaces was investigated by angle resolved XPS method. The shifts of Au 4f core electron binding energy were negative for Au deposited on Pt and higher in magnitude than positive shifts observed for Au on Re. The shifts did not depend on the structure of the Pt substrate surface but were affected by structure of the Re surface. More than 5 equivalent monolayers of Au on Pt were required to obtain bulk-like spectra while 2 monolayers were sufficient for Au/Re. The results suggested formation of several monolayers thick interface Au–Pt alloy in contrast to abrupt Au/Re interface. The measured trends in Au 4f core level shifts were reproduced by those calculated using local density functional method within the initial state approximation.