4pand4dAuger spectra of atomic and solid Yb

The $N_{4,5}{N}_{6,7}X(X=N_{6,7} or O_{2,3})$ and $N_{2,3}{N}_{4,5}{N}_{6,7}$ Coster- and super-Coster-Kronig-type Auger spectra of ytterbium have been investigated both experimentally and theoretically. The spectra have been measured in vapor and solid phases using electron-impact excitation. Owing to the strong lifetime broadening of the $4p$ and $4d$ initial levels, the spectra are characterized by broad structures. Energies and intensities of the line components have been calculated in the mixed-coupling scheme applying $j-j$ coupling in the initial state and intermediate coupling in the final states. The calculated and experimental results have been found to be in reasonable agreement. The observed linewidth of the $4d$ Auger lines is 4.2 eV (full width at half maximum) and 5.0 eV for the vapor phase and the solid phase, respectively. The relative energies and intensities of the individual Auger lines are found to be essentially the same for the vapor and the solid phases; therefore, the quasiatomic rather than the bandlike model seems to be a correct description of the solid-state spectra. Comparison between vapor- and solid-phase spectra gives after correction by work function a vapor-metal Auger energy shift of 16.1 eV. This shift can be reproduced satisfactorily in theory by using the simple semiempirical thermochemical model for the extra-atomic relaxation.