Potential-Barrier Effects in Photoabsorption. II. Interpretation of Photoabsorption Resonances in Lanthanide Metals at the4d-Electron Threshold

The resonances in the photoabsorption spectra of the lanthanides near the $4d$ absorption edge are interpreted as transitions of the type 4f¹⁰4fN→4d⁹4fN+1. Calculations of the 4d⁹4fN+1 energy levels and relative gf values for these transitions are shown to be in good agreement with the observed absorption spectra. The assumption that the lanthanides occur in trivalent form (with the exception of Eu and Yb) in the metallic solid state is confirmed by these results.