Intermediate valence in Yb compounds probed by 4fphotoemission and resonant inelastic x-ray scattering

Experimental data from $4f$ photoemission and resonant inelastic x-ray scattering experiments on the intermediate valent compound YbRh₂Si₂ have been compared with results of theoretical simulations. It was found that the high-energy excitations inherent to these techniques affect the spectral intensities related to different $4f$ configurations differently. Although the final states in $4f$ photoemission and x-ray absorption or resonant inelastic x-ray scattering are rather unalike, a comparable influence was found for both cases. Higher occupied $4f$ shells seem to be energetically favored in the excited states and appear overemphasized in the spectrum as compared to the ground state. For a quantitative Yb valence determination from x-ray spectroscopies, diagrams are suggested that seem to be applicable also for other intermediate valent Yb compounds.