Resonant photoemission study of UNi5-xCux

Valence-band spectra of the intermetallic compounds UNi5-xCux (x=0.0, 2.5, and 5) have been measured using synchrotron radiation in the energy range 10 to 130 eV. In all compounds the 5f-derived valence-band density of states is pinned to the Fermi energy. In contrast to earlier work, no splitting of the U 5f emission due to different final-state 5f configurations is observed in UCu5. This points towards an itinerant description of the 5f electrons in these compounds. A decrease in the intensity of the Ni two-hole satellite is observed in going from Ni metal and UNi5 to U(Ni0.5Cu0.5)5 which can be related to a filling of the Ni d band. Furthermore, a shift of the Ni satellite energy by 1.3 eV towards higher binding energies occurs in U(Ni0.5Cu0.5)5. © 1982 The American Physical Society.