High-resolution Ce 3d-4f resonant photoemission studies have been performed
for a valence-fluctuating CeRu2. The bulk-sensitive Ce 3d-4f resonance spe
ctrum near the Fermi level shows a band character of the 4f state of CeRu2
beyond a framework of the single impurity model. We also show that the Ru 4
d spectral line shape of CeRu2 is different from that of LaRu2 due to a str
ong Ru4d-Ce4f hybridization. (C) 2000 Elsevier Science B.V. All rights rese
rved.