Magnetic coupling in Co/Cu multilayers: Field-dependent antiferromagnetic ordering investigated by resonant X-ray scattering

By simultaneous measurements of sample resistance and of X-ray resonant scattering, we tried to establish a direct correlation between magnetoresistance (MR) and antiferromagnetic (AF) order in a Co/Cu metallic multilayer. Field-dependent scattered intensity has been measured in a geometrical configuration corresponding to the Bragg peak coming from the AF coupling, at a photon energy close to the Co L-3 absorption edge (hv = 776.5 eV). The comparison between measurements of the scattered intensity and of the resistance clearly shows a direct correlation between AF order and MR.