RESONANT MAGNETIC-X-RAY SCATTERING IN UPD2SI2 AT THE URANIUM L-2,L-3 EDGES

The nature of the resonant magnetic x-ray-scattering processes at the uranium L-2 and L-3 edges of UPd2Si2 has been studied. The different p olarization dependences of the electric dipole and quadrupole transiti ons are used to distinguish the two channels. The temperature variatio n, together with the angular dependence of the magnetic reflections de monstrate the dipolar origin of the resonance at the uranium L-2 and L -3 edges of UPd2Si2. Resonant magnetic x-ray scattering at these edges thus explores the spin polarization of the valence 6d band and allows the study of the magnetism of electronic d orbitals separately from f levels probed at the M-4 and M-5 edges in dipole transitions. The ene rgy profiles of the two L edges are different. A single resonance is o bserved at the L-2 edge. The line shape at the L-3 edge shows two dist inct contributions, both of dipolar type, which may be due to the infl uence of the core hole on the density of states of 6d levels. The ener gy of the maximum of the resonant intensity in both profiles correspon ds to the inflexion point in the respective absorption coefficient cur ve. An effort to put the scattering amplitudes on an absolute scale ha s been made in order to compare with theoretical calculations. [S0163- 1829(98)07037-4].