Surface and bulk electronic structure of Ce metal studied by high-resolution resonant photoemission

High-resolution resonant photoemission (PE) at the 4d{→}4f and 3d{→}4f thresholds is applied to study the electronic structure of Ce metal. Due to the different surface sensitivities, the resulting 4f PE spectra, which are almost free of non-4f background, reflect directly a substantial change in 4f electronic structure of {α}-Ce metal towards {γ}-like behavior at the surface. This finding resolves a longstanding discrepancy between the results of surface-sensitive 4f PE and those of bulk model calculations. Pure surface and bulk 4f PE signals are derived for {α}-Ce metal.