X-Ray Scattering at Lanthanide M5 Resonances: Application to Magnetic   Depth Profiling
  Quantitative analyses of x-ray scattering from thin films of Ho and Dy metal at the M_5 resonances result in values of the optical constants and the magnetic scattering lengths f_m, with f_m as large as 200 r_0. The observation of first- and second-order magnetic satellites allows to separate f_m into circular and linear dichroic contributions. This high magnetic sensitivity, in conjunction with the tunable x-ray probing depth across the resonance can be applied to monitor depth profiles of complex magnetic structures, as e.g. of helical antiferromagnetic domains in a Dy metal film. 
H. Ott, C. Schuessler-Langeheine, E. Schierle, A. Yu. Grigoriev, V.   Leiner, H. Zabel, G. Kaindl, and E. Weschke