The first three peaks correspond to Ce 3d5/2 and the last two peaks correspond to Ce 3d3/2. An additional peak at a binding energy of 916.6 eV was observed in the survey scan. The binding energies of these peaks match very closely the reported values of the Ce 3d six peaks of cerium in the Ce4+ oxidation state[5]. These results indicate that the films consisted of pure CeO2.This is further supported by the presence of the peak at 916.6 eV, which is considered as a finger print of the CeO2 phase [7].