Satellites on the low-binding-energy side of core-level photoelectron emission due to extra $4f$ screening are a well-known feature in the x-ray photoelectron spectra of valence fluctuation materials and rare-earth metals. A notable exception is Eu metal, where up to now no low-binding-energy satellite has been observed. In this paper we show that in Eu metal the $4d-4f$ resonance can decay via a resonant Auger decay, which is not a constant kinetic-energy feature due to a rapid change of the strength of $4f$ screening with excitation energy, establishing a low-binding-energy replica of the $5p$ core-level photoelectron emission.

• Received 28 July 1999

DOI:https://doi.org/10.1103/PhysRevB.60.16346