Surface Chemistry of Zirconia Nanopowders Doped with $Pr_2O_3$: an XPS Study

Zirconia nanopowders of tetragonal crystallographic structure doped with $Pr_2O_3$ were prepared by the microwave-assisted hydrothermal synthesis and coprecipitation method. The surface compositions were studied by X-ray photoelectron spectroscopy. The nanopowder particles appear to be inhomogeneous in their structure: for the surface region an enrichment with praseodymium is detected by X-ray photoelectron spectroscopy measurements. This allows the assumption of a core-shell-like structure of single nanopowders particles. The X-ray photoelectron spectroscopy studies confirm also $Zr^{4+}$ and $Pr^{3+}$ as main oxidation states of zirconium and praseodymium in the studied compounds.