Soft X-ray scattering dominates emission near the giant resonance of the rare earth compounds

Inelastic scattering of 4d electrons near the 4d-4f thresholds of Gd2O2S an d Tm2O3 is studied with monochromatic synchrotron radiation excitation. The emission is dominated by inelastic scattering. We observe two energy loss mechanisms, which are 4f inner-shell excitations (4d(10)4f(n)-->4d(9)4f(n+1 )-->4d(10)4f(n)) and 5p-4f excitations (4d(10)5p(6)4f(n)-->4d(9)5p(6)4f(n+1 )-->4d(10)5p(5)4f(n+1)). Our atomic calculations are in excellent agreement with the experimental emission spectra indicating strong localization and a low degree of correlation of the 4f electrons. Inelastic scattering can b e used to elucidate the relative partial cross sections for the contributin g transitions. (C) 2000 Elsevier Science B.V. All rights reserved.