J. Phys. IV France 7 (1997) C2-415-C2-420
Strong Final State Effects in L2,3 XMCD of Ionic Rare Earth MaterialsJ.B. Goedkoop1, A. Rogalev1, M. Rogaleva1, C. Neumann1, J. Goulon1, M. van Veenendaal2 and B.T. Thole1
1 European Synchrotron Radiation Facility, BP. 220, 38043 Grenoble cedex, France
2 European Synchrotron Radiation Facility, BP. 220, 38043 Grenoble cedex France
The La XMCD spectra of rare earth insulating systems show line shapes that look like a derivative of the nearedge XAS spectra. This line shape is shown to be due to intra-atomic final state Coulomb interactions between the 2p → 5d excited photoelectron and the magnetically aligned 4f shell. An atomic multiplet calculation starting from a 4fN5d0 initial state gives good agreement with the observed line shapes. The experimental fact that the temperature dependence of the XMCD follows that of the 4f moment supports such a local description. Furthermore, an analysis in terms of spectral moments based on the 5d0 assumption yields sum rules for the first moments of the edges that explain the trends in literature data for metallic systems.
© EDP Sciences 1997