Abstract
We follow the cluster formation when depositing less than 2 monolayers Cu onto a monocrystalline αAl2O3 (0001) stoichiometric surface, by combining XPS and X-ray absorption spectroscopy at the Cu K edge (EXAFS, XANES). An estimate of the evolution of cluster size with copper deposition is given from XANES and EXAFS data. The variation of the Cu Auger parameter, measured from the XPS spectra, shows a continuous increase, attributed to the continuous increase of cluster size with copper deposition.