Photoemission study of the epitaxial Ce/Pd(100) interface

The electronic state of cerium has been investigated by core-level and vale nce band photoemission spectroscopy in ultra-thin films of a Ce-Pd. monocry stalline compound obtained by epitaxial growth. Careful characterization of the surface leads us to the conclusion that the Ce configuration admixture is strongly reduced in the surface layer. By evaporating one extra monolay er of Pd, we were able to obtain core-level photoemission spectra without a ny surface contribution and to evidence an exceptional configuration mixing for the bulk ground state. The 4f spectral function obtained from photoemi ssion measurements at the N-4.5 threshold also exhibits a very singular beh avior and shed some new Light on the description of highly-hybridized 4f st ates in Ce compounds.