Resonant Photoemission at the2pEdges of Ni: Resonant Raman and Interference Effects

Unambiguous evidence for resonant photoemission in Ni is presented. Interference effects are identified at the $2p$ edges for the valence band and the 6 eV satellite. A rapid transition from a resonant Raman to an Auger-like regime shows that the core-excited states above threshold are not localized enough to significantly enhance the photoemission intensity, implying a large fraction of incoherent intensity. The results indicate that the appearance of interference effects does not require strong localization of the intermediate state.