Ce 5d magnetic profile in Fe/Ce multilayers for the α and γ-like Ce phases by x-ray resonant magnetic scattering -: art. no. 134420

The in-depth distribution of the induced 5d magnetic moments across the Ce layers in Fe/Ce/La/Ce, Fe/La/Ce/La and Fe/CeH2-delta multilayers has been investigated by x-ray resonant magnetic scattering (XRMS) at the Ce L-2 edge. The determination of the composition profile across the period of the multilayer is required for a quantitative analysis of XRMS and has been derived from x-ray resonant reflectivity measurements. In Fe/Ce/La/Ce and Fe/La/Ce/La multilayers, Ce adopts an alpha-like electronic configuration and the local magnetization, across the Ce layer, is found to be highly nonuniform. The Ce 5d magnetic profile shows an oscillating behavior with an amplitude decreasing from the Fe interface in Fe/Ce/La/Ce. Conversely, in Fe/La/Ce/La, where the Ce atoms are not in direct contact with Fe atoms, it presents an oscillatory profile with, however, a nearly constant amplitude. In Fe/CeH2-delta multilayers, where hydrogen leads to a strain relaxation and to a 4f relocalization (Ce gamma-like configuration), a nonoscillating decreasing profile has been observed. These experiments allow one to evidence an antiferromagnetic component in a alpha Ce ultrathin layer and a sharply decreasing induced magnetization due to 5d-3d hybridization at the interface.