X-ray photoemission spectra of the 4d levels in rare-earth metals

High resolution photoemission spectra of the 4d levels in the rare-earth metals are reported. The metals with partially filled 4f shells display very complicated structure due to multiplet splitting, while those with the 4f0 or 4f14 configuration exhibit only spin-orbital splitting. A detailed analysis is given for the 4f7 metals europium and gadolinium.