3<i>d</i>and 4<i>d</i>x-ray-photoelectron spectra of Pr under gradual oxidation

Abstract

The 3d and 4d core levels and the valence band of a Pr foil have been investigated by photoelectron spectroscopy under gradual oxygen influence. ${\mathrm{Pr}}_{2}$${\mathrm{O}}_{3}$ is formed on the Pr surface in the presence of 1\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}8}$ Torr oxygen after half of an hour. The Pr core-level spectra and the x-ray photoemission spectroscopy valence bands are compared with the respective x-ray-photoemission spectra of ${\mathrm{Pr}}_{2}$${\mathrm{O}}_{3}$, ${\mathrm{Pr}}_{6}$${\mathrm{O}}_{11}$, and ${\mathrm{PrO}}_{2}$.