Hard x-ray photoemission and optical spectroscopies have been performed on YbS and Yb metal to determine the precise f -electron occupation. A comparison of the photoemission spectra with the energy-loss functions in bulk and surface, obtained from optical reflectivity, enables us to distinguish between the energy-loss satellite of Yb2+ peak and the Yb3+ multiplet. The results clearly indicate a purely divalent Yb state except for the surface of YbS which is altered by oxidation. We demonstrate that the present method is highly reliable in identifying the electronic structure and the mean valence in f -electron systems.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - Nov 19 2008|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics