Temperature-Dependent Reduction of Epitaxial Ce1–xPrxO2−δ (x = 0–1) Thin Films on Si(111): A Combined Temperature-Programmed Desorption, X-ray Diffraction, X-ray Photoelectron Spectroscopy, and Raman Study

The inherent properties of epitaxial oxide thin-film layers have attracted the intense interest of different research fields, such as catalysis and microelectronics. The focus of this work is the temperature-dependent oxygen release, oxygen vacancy formation, and lattice rearrangement of Ce1–xPrxO2−δ thin films with systematic stoichiometry variation (x = 0–1) and oxygen deficiency (δ > 0) on Si(111). The mixed oxide layers were heteroepitaxially grown by coevaporating molecular beam epitaxy. To observe the oxygen release, temperature-programmed desorption was performed. Furthermore, laboratory-based X-ray diffraction measurements were carried out after several annealing steps to investigate the crystal structure rearrangement. The contribution of Ce4+/Ce3+ and Pr4+/Pr3+ redox systems to the oxygen release and lattice rearrangement was clarified by X-ray photoelectron spectroscopy. Finally, Raman spectroscopy was performed to detect structural defects in the oxide lattice (i.e., oxygen vacancies and MO8-c...