Core electron energy loss spectra in metallic La

The calculation of relative intensities for electron excited 4d10→4d9nf, epsilon f transitions in metallic La has been discussed on the basis of the inelastic electron mechanism invoked by Netzer et al. [Phys. Rev. Lett. 51, 211(1983)]. The analysis indicates that for incident electron energies far away from the core level excitation threshold, direct Coulomb interaction processes are the most prominent; as the incident electron energy approaches threshold, exchange processes feature as prominently, giving support to the stage-wise breakdown of selection rules in electron impact excitation suggested by Netzer et al. (author)