MOMENTUM-DEPENDENT EFFECTS IN 4F PHOTOEMISSION SPECTRA FROM STRONGLY CORRELATED CEBE13

We have studied the mixed-valent compound CeBe13 using a combination o f high-resolution angle-resolved resonant photoemission and x-ray abso rption. Based on the angle and temperature dependence of the intensity of the f(1) peak at the Fermi level, we conclude that the 4f state is most likely a narrow band with a bandwidth of similar to 50 meV, and may cross the Fermi level. The temperature dependence of the valence b and photoemission spectroscopy can be accounted for by conventional th ermal broadening effects. A mean valence of v similar to 3.04 is extra cted from M(4,5) absorption spectra which agrees with L(III) edge meas urements, however the temperature dependence is negligible. A large am plitude anisotropy is observed in the f(0) peak, as well as about 0.1 eV of dispersion. Residual gas dosing in the submonolayer regime sugge sts that much of the f(0) intensity is surface related.