MOMENTUM-RESOLVED PHOTOEMISSION OF THE KONDO PEAK IN AN ORDERED CE-CONTAINING ALLOY

A comparison of uv-photoemission spectra recorded from the surface all oys Pt(111)(root 3x root 3)R30 degrees Ce and Pt(111)(2 x 2)La allows the contribution from the 4f electrons to be seen easily. The valence- band structure of these two surfaces is very similar, and the most obv ious 4f contribution in high-resolution photoemission spectra of the C e-containing alloy is the tail of the Kondo peak cut at E-F. Within th e limits of our measurement, no dispersion of this feature in the occu pied regime is detected. The Kondo peak displays a marked intensity de pendence on the emission angle, suggesting that hybridization is prese nt in only a limited part of reciprocal space. The temperature depende nce of this near-E-F feature supports this interpretation. [S0163-1829 (97)50942-8].