XPS STUDIES OF DAMAGE INDUCED BY X-RAY IRRADIATION ON CEO2 SURFACES

Core-level photoemission spectra show that CeO2 is partially reduced to Ce2O3-like phases after prolonged AlK? X-ray exposures. It is suggested that the damage is a result of a locally intense heating of the first few layers of ceria. Experimental evidence is given that some of the Ce 3d XPS features, commonly ascribed in the literature to excited electronic states of CeO2, are actually X-ray induced damage peaks.