SURFACE ELECTRONIC-STRUCTURE OF CECO2, CERH2 AND CERH3 PROBED BY VALENCE-BAND RESONANT PHOTOEMISSION SPECTROSCOPY

The 4f surface versus bulk electronic structure of three strongly hybridized Ce intermetallic compounds (CeCo2, CeRh2 and CeRh3) is investigated by exploiting the 4f photoemission resonant enhancement at the Ce 3d-4f and Ce 4d-4f thresholds. The much higher surface sensitivity at the shallow 4d threshold allows to extract the surface and bulk 4f electronic structure. Our results show a decreasing of the hybridization strength at the surface as compared to the bulk. The analysis of the whole set of results highlights the effect on the 4f spectral function obtained by varying the Ce metallic partner in the same crystal structure (CeCo2 versus CeRh2) and by changing the stoichiometry in the Ce-Rh phase diagram (CeRh2 versus CeRh3).