Characteristic temperature dependence of the 4f occupancy in the Kondo system CeSi2

We present a Ce-L x-ray absorption spectroscopic study (XAS) of CeSi at different temperatures. The extracted Ce 4f occupancy shows a strong dependence upon temperature that qualitatively agrees with theoretical expectations based on the single-impurity Anderson model. We additionally discuss the reliability of L XAS performed on nearly trivalent rare-earth compounds in comparison with other high-energy spectroscopy techniques. © 2001 The American Physical Society.