Electronic and magnetic interfacial states of Ag in an Ni81Fe19/Ag coupled multilayer

Studies of the Ag induced magnetic moments at the interfaces in an [Ni 81 Fe 19 (29 Å) / Ag(11 Å)] 135 multilayer by x-ray magnetic circular dichroism (XMCD) and x-ray resonant magnetic scattering (XRMS) at the Ag L 2,3 edges are reported. This allows us to quantify the interfacial magnetic moments as well as the extension through the silver layer. From the experimental XMCD spectra and thanks to the use of full relativistic band structure calculations, we succeed in extracting quantitative spin and orbital magnetic moments held by the 4d states of silver. Moreover, we show that, although silver has an almost full 4d band, magneto-optical sum rules can be safely applied in the case of the noble metal L edges. We find from XMCD that Ag is polarized by Ni 81 Fe 19 and has a total magnetic moment of 0.0136 μ B spatially averaged over the 11 Å layer thickness. XRMS analysis indicates that this induced polarization is enhanced at the interface but remains present inside the whole Ag layer, demonstrating the existence of an indirect coupling between the NiFe layers through the non-magnetic spacer.