A THEORETICAL FRAMEWORK FOR ABSORPTION (DICHROISM) AND THE RESONANCE-ENHANCED SCATTERING OF X-RAYS BY MAGNETIC-MATERIALS .3. CONTRIBUTIONS FROM ATOMIC SPINS

A report is given of a study of the resonant contribution to the scatt ering length for x-rays, evaluated using an atomic picture of the elec trons. Armed with the scattering length one can calculate the attenuat ion coefficient, dichroic signal and cross-sections for the elastic an d inelastic scattering of x-rays by magnetic materials. The formulatio n is more finely honed than the one used in two previous studies. The additional information in the scattering length relates to the spins o f the electrons in the unfilled valence shell. For the d(n) and f(n) c onfigurations, tables of Racah unit spherical tensors are provided for ground states determined by Hund's rules.