Photoelectron and bremsstrahlung-isochromat studies of 4f levels in -Ce, CeAl3, CeSn3, and CePd3

Bremsstrahlung-isochromat spectra (BIS) show the 4f levels in -Ce, CeAl3, CeSn3, and CePd3 to be localized. The 4f2 states are centered about 5 eV above EF in all cases. The BIS spectra of -Ce, CeSn3, and CePd3 all contain evidence for empty 4f1 levels just above EF. The opinion is expressed, that the position of the occupied 4f1 levels still cannot be unambiguously identified.