XPS and DRIFTS study of cerium in Ce-Si-Al-O-N glasses

Glasses belonging to the Ce-Si-Al-O-N system have been prepared by heating physical mixtures of CeO2, AlN and SiO2 under N-2. A Sample in which Al2O3 has been replaced by Al2O3 was also prepared for studying the influence of the nitrogen content in the oxidation state of cerium. X-ray Photoelectron Spectroscopy (XPS) and Diffuse Reflectance Fourier Transform Spectroscopy (DRIFTS) of the prepared glasses indicated that the amount of Ce4+ ions present in the glass matrix is very low, if any, in all samples. The presence of nitrogen in the glass network alters the electronic density of all the elements present in the glass, as demonstrated by XPS, but does not modify the coordination polyhedra of cerium that remains unchanged whatever the nitrogen content of the glass network.