Correlation effects in 3d transition metals: Presence of a two-hole core-satellite in cobalt

Photoemission spectra of the 2p-level have been recorded from evaporated films of the 3d transition metals vanadium, chromium and cobalt. Structures on the high binding energy side of the spectra are observed; cobalt shows a weak satellite structure that resembles the well-known shakeup satellite in the nickel core level spectrum, only less intense, whereas the core level spectra of V and Cr only show satellites due to collective electron excitations.