Optical spectra of gadolinium and dysprosium: study of the 5p thresholds

The authors have performed optical measurements by multi-angle reflectance between 2 and 30 eV on gadolinium and dysprosium films condensed on glass substrates, in a vacuum of 2*10 -10 Torr. Optical constants have been determined with the help of the multi-angle method and the Kramers-Kronig analysis. The optical conductivity, sigma , optical constants, epsilon 1 and epsilon 2 , N eff and energy loss functions have been deduced. The authors have compared their results between 2 and 18 eV with those of Erskine and Flynn (1976) and have shown that the shake-up structure for the 5p thresholds comes from a 5p and a 4f open shell coupling.