| Popis: |
The intention of this work is to shed light on two much discussed topics in the study of rare earth oxides (REO) by hard x-ray photoelectron spectroscopy (HAXPES): (i) Due to the comlex spectral shape of the Ce3d region, there have been many discussions on proper approaches to determine the concentration of Ce$^3+$ and Ce$^4+$ species in CeO$_x$ over the last decades. (ii) Recently, the true electron structure of rare earth oxides gained new attention, since ab intio calculations showed the necessity of considering additional inter atomic charge transfer to Ce5d levels. Using HAXPES and resonant HAXPES, the question of the true electronic structure of rare earth oxides is approached from the experimental side. As a third topic, the obtained results for cerium oxide and praseodymium oxide are applied in order to investigate the plasma oxidized mixed oxide Ce$_x$Pr$_1−x$O$_2−δ$ grown on Si(111) during thermal reduction. |
