Hybridization effects in 4f systems as observed by photoemission spectroscopy

Yuri Kucherenko

Institute for Metal Physics, Academy of Sciences of Ukraine, Vernadsky Str. 36, 03142 Kiev, Ukraine

Hybridization of the 4f electrons with valence-band states can lead to giant effects resulting in energy splittings of 4f emission by several eV. The phenomena are described quantitatively in the framework of a single-impurity Anderson model. The role of the realistic description of the valence-band DOS, surface vs. bulk effects as well as resonance channel effects are discussed. The calculated results are compared with the spectra measured for the rare-earth - transition-metal compounds. Some experimental results for angle-resolved photoemission are interpreted with a simplified periodic Anderson model.