Momentum-resolved photoemission of the Kondo peak in an ordered Ce-containing alloy

A comparison of uv-photoemission spectra recorded from the surface alloys 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 obvious 4f contribution in high-resolution photoemission spectra of the Ce-containing alloy is the tail of the Kondo peak cut at E-F. Within the limits of our measurement, no dispersion of this feature in the occupied regime is detected. The Kondo peak displays a marked intensity dependence on the emission angle, suggesting that hybridization is present in only a limited part of reciprocal space. The temperature dependence of this near-E-F feature supports this interpretation. [S0163-1829(97)50942-8].