Te and Se impurities influence on structure of ceria oxide surfaces


Purpose. The aim of our work is to detect the influence of chalcogenide impurities on the cerium oxide CeO2 structural properties by X-ray photoelectron spectroscopy (XPS).
Methods. To obtain of the samples the mixture of CeO2+Te and CeO2+Se (40+20 mg) powders in sealed ampoules were kept at a pressure of 0.13 Pa and temperatures of 200, 300, 400˚C during 12 hours. Al Kα radiation (1486.6 eV) was used to measure the XPS core levels spectra of Ce 3d, O 1s, Se 3d, Te 3d and C 1s with total resolution of 1 eV. Curve fitting was performed after a Shirley background subtraction by a Lorenzian–Gaussian method.
Results. Two types of research were conducted: measurements of X-ray photoelectron spectra of CeO2 with Te and XPS spectra of CeO2 with Se samples. The analysis of the measured spectra showed that the temperature of the samples synthesis for cerium oxide with Te has influence weakly on chemical bonds. For samples with selenium impurities, the dependence of Се 3d and Se 3d core level spectra on the synthesis temperature is higher, but no specific pattern was observed.
Conclusions. CeO2+Te and CeO2+Se samples were obtained. XPS spectrum of these samples were measured. The Ce 3d and Se 3d core level spectra of cerium oxide with Se indicate the formation of CeSe compound. The formation of cerium telluride is shown by the Te 3d core level spectra. The O 1s core level spectra of CeO2+Te and CeO2+Se indicate the presence of oxygen-carbon compounds in all samples

Keywords: zerium oxide, chalcogenides, X-ray photoelectron spectroscopy, chemical compounds