Surface and bulk 4f photoemission spectra of CeIr2

Resonance photoemission spectroscopy was performed on CeIr2 at the Ce 4d--> 4f and 3d-->4f core thresholds. We also obtained angle-dependent 4d-->4f re sonant spectra. Surface and bulk Ce-4f spectra were derived using differenc es both in the angle-dependent spectra and in the resonant spectra at the t wo different thresholds. The surface and bulk spectra are different dependi ng on the derivation methods, and the spectra derived from the angle depend ence are more consistent with theoretical spectra using the Gunnarsson-Scho nhammer method of the Anderson impurity model, which implies that the two r esonant spectra may reflect different 4f-removal spectra. [S0163-1829(99)02 416-9].