ELECTRONIC-STRUCTURE OF COPPER PARTICLES SUPPORTED ON TIO2, GRAPHITE, AND AL2O3 SUBSTRATES - A COMPARATIVE-STUDY

X-ray photoelectron spectroscopy (XPS) and X-ray induced Auger electron spectroscopy (XAES) have been employed to investigate the electronic structure of copper particles deposited on TiO2, graphite, and Al2O3 substrates. While at high coverages the spectral features are similar to those of bulk Cu, at low coverages these features are sensitive to both cluster size and final state relaxation effects. We have estimated the effective coulomb interaction energy, Ueff, between the two holes created in the valence band as a result of the Auger process, and observe that it is strongly dependent on the substrate and the neighboring Cu atoms. © 1993 Academic Press, Inc.