ROLES OF DYNAMIC SCREENING BY THE 5D AND 4F-ELECTRONS IN THE OPTICAL-EXCITATION SPECTRA OF CE-PNICTIDES

The core-level and the 4f-valence electron photoemission spectra of CeSb are analyzed considering the screening by both the 5d and the 4f-electron. The calculation is done based on the cluster model. The screening by the 5d-electron leads to the energy dependent reduction of the mixing value between the 4f and the band-electrons. As a direct evidence of the dynamical screening by the 5d-electron, a satellite is expected at about 10 eV higher binding energy than the main peak with about a half of intensity for the main peak. This satellite corresponds to the p-d anti-bonding state and explains the peak seen in the experiment which has been attributed to the plasmon side band. Similar satellite is expected also in the core-level XPS of the Sb site.