Raising of Discrete Levels into the Far Continuum

Abstract

Broad peaks observed in the photoabsorption spectra of rare earths \ensuremath{\sim}10-20 eV above the $4d$ edge are attributed to transitions $4{d}^{10}4{f}^{N}\ensuremath{\rightarrow}4{d}^{9}4{f}^{N+1}$. Exchange interaction splits the $4{d}^{9}4{f}^{N+1}$ configuration and raises some multiplets by \ensuremath{\sim}20 eV. Autoionization to $4{d}^{9}\ensuremath{-}4{f}^{N}\ensuremath{\epsilon}f$ broadens the high levels. The interpretation extends to $p\ensuremath{\rightarrow}d$ processes observed in the absorption of synchrotron light by transition elements.