Changes in 5d band polarization in rare-earth compounds

X-ray resonant magnetic scattering has been used to examine the magnetic interactions coupling the rare earth and iron sublattices in the antiferromagnetic compound DyFe4Al8. Dramatic differences are observed in the temperature dependencies of the energy profiles at resonance depending on whether the photon energy is tuned to the Dy L-2 or L-3 absorption edge. In particular, for temperatures increasing from 10 K, the resonant scattering intensity at the L-3 edge decreases whereas that at the L-2 edge rises. We suggest a physical model capable of reproducing these phenomena.