Profile of the induced 5d magnetic moments in Ce/Fe and La/Fe multilayers probed by x-ray magnetic-resonant scattering

The element and electronic shell selectivity of x-ray resonant magnetic sca ttering (XRMS) has been used to investigate the profile of the spin polariz ation of the 5d electronic states of Ce and La across the rare-earth layers in Ce/Fe and La/Fe multilayers. The magnetic contributions to the diffract ed intensities have been measured at low angles, at the L-2 edge of the rar e earth. In agreement with previous results from x-ray magnetic circular di chroism (XMCD) experiments, the La 5d polarization is found to be localized right at the interfaces with the Fe layers, as it is expected from a direc t hybridization with the Fe 3d states. In the case of Ce/Fe multilayers whe re Ce is in an ar-like electronic state with a complex behavior of the 5d m agnetic polarization, the XRMS results obtained for two samples with 10 and 22 Angstrom thick Ce layers indicate that the Ce 5d polarization decreases slowly from the interfaces towards the center of the layers. This is in ag reement with previous XMCD results. However, at least for the two samples w hich have been investigated, XRMS also suggests that the Ce 5d polarization oscillates across the Ce layer with a period equal to the (111) interplana r distance in alpha fcc Ce. Though compatible with the XMCD findings, this oscillating behavior cannot be derived from its dependence on the Ce layer thickness because of the decrease of the magnetic polarization which preven ts us from observing changes in the sign of the XMCD amplitude. [S0163-1879 (99)04637-8].