DISPERSION OF F-STATES IN U-METAL AND CERH3

Photoemission (PE) experiments on ordered films of U-metal and RE-Rh s urface compounds (RE=Ce, La) are reported. For U-metal, formation of a new close-packed phase is observed. PE spectra of the ordered U-film reveal a clear dispersion of the U Sf-derived states. The experimental data are in excellent agreement with the results of relativistic LDA band-structure calculations. The bandlike properties of the U 5f state s stem from f-f interaction rather than from f-d hybridization as migh t be expected for 4f-derived bands of Ce-compounds. In CeRh3, resonant angle-resolved PE spectra reveal a weak energy shift of the Fermi-lev el peak, which may be ascribed to a dispersive behaviour of the Ce 4f states. Data on LaRh3 were used for discrimination of 5d- and 4f-relat ed effects in the PE spectra of CeRh3. (C) 1998 Elsevier Science S.A.