Observation of resonance recombination lines in electron excited auger spectra of Gd

Combined measurements of electron excited N_4,5 Auger spectra and photoelectron emission on clean and oxidized Gd lead to a distinction between Auger lines originating from 4d → continuum and 4d → 4? resonance excitations. Several Auger structures are identified as due to the direct recombination of 4d⁹4?⁸ states with the 4f and valence electrons. The shape of the most prominent Auger line for oxidized Gd agrees perfectly with the Fano profile of the 4? photoemission intensity.