Electronic Band Structure of Gd: A Consistent Description

The dispersion of the Gd $\left(5d6s\right)$-valence bands has been investigated by means of spin- and angle-resolved photoemission. The spin analysis of various spectral features shows that their weak dispersion and unusual broadening is due to the photoelectron lifetime rather than to correlation induced band narrowing as previously proposed. These results resolve a long-standing discrepancy between theoretical and experimental descriptions of the rare earth band structure.