Abstract
Cerium oxide doped by a noble metal has been researched intensively for its high catalytic activity. In the presented study, Rh-Ce-O and CeOx thin films were deposited onto SiO2 and Cu substrates by radio-frequency magnetron sputtering.
Thermal stability of the films was investigated by photoelectron spectroscopy techniques. Our results show that the substrate has a great influence on the stability of the overlayers.
Rh-Ce-O deposited on Cu decomposes into rhodium and cerium oxide separate phases above 600 K. In contrary, the Rh-Ce-O film on SiO2 remains stable up to 800 K, but silicon migrates from the substrate into the film, forming cerium silicate.
We suggest that a strong interaction between SiO2 substrate and Rh-Ce-O, or CeOx films, could be responsible for higher thermal stability compared to films deposited onto Cu.