Soft X-Ray Resonant Magnetic Scattering from a Magnetically Coupled Ag/Ni Multilayer

X-ray resonant magnetic scattering experiments using linear and circular polarized light were performed at the Ni $L_{2,3}$ absorption edges on a Ag $/$Ni multilayer. A superlattice magnetic peak, due to the antiferromagnetic coupling between Ni layers, is evidenced. In the case of a ferromagnetic coupling, large changes in the charge peak (up to 15%) are observed upon reversal of the direction of the magnetic field. The magnetic scattering amplitude is evaluated to ${8r}_0$ per nickel atom. Sum rules have been applied for the first time to the energy-dependent magnetic amplitude.