4f- and core-level photoemission satellites in cerium compounds

The two $4f$-derived photoemission features recently observed for Ce pnictides are identified with hybridized $4f$-hole and ligand-hole final states. Simple expressions obtained for a $\mathrm{Ce}{X}_6$ cluster explain the change in the relative intensity of the two $4f$ features without energy shifts. Analogous expressions are presented for the satellite structures of the $3d$ core x-ray-photoemission spectra of rare-earth compounds, assuming a "poorly screened" core-hole state and a core-hole state screened by $4f$-electron—ligand-hole excitations with hybridization between these core-hole states. It is shown that in some lanthanum compounds the high—binding-energy line is due to a "well-screened" core hole arising from the ligand $\to 4f$ shakeup process while for other rare-earth compounds the "well-screened" peak lies at lower binding energies. It is also suggested that the extra intensities in the bremsstrahlung-isochromat spectra of Ce and its alloys are due to final-state effects arising from hybridized $4f^2$ and $4f^1$ configurations.