Momentum-dependent effects in 4f photoemission spectra from strongly correlated CeBe13

We have studied the mixed-valent compound CeBe13 using a combination of high-resolution angle-resolved resonant photoemission and x-ray absorption. 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 band photoemission spectroscopy can be accounted for by conventional thermal broadening effects. A mean valence of v similar to 3.04 is extracted from M(4,5) absorption spectra which agrees with L(III) edge measurements, however the temperature dependence is negligible. A large amplitude anisotropy is observed in the f(0) peak, as well as about 0.1 eV of dispersion. Residual gas dosing in the submonolayer regime suggests that much of the f(0) intensity is surface related.