Effect on alloying at the Fe/Ni(001) interfaces on the interlayer exchange coupling

We investigate the stability of various ordered FeNi alloys at the interfaces of Fe/Ni superlattices by using ab initio density functional calculation. We consider an Fe<Subscript>0.5</Subscript>Ni<Subscript>0.5</Subscript> ordered alloy of one or two monolayers thick at different positions beyond the interface and the possibility of an interdiffusion of a complete monolayer of Ni(Fe) in Fe(Ni) slab. An interfacial atomic layer of Fe<Subscript>0.5</Subscript>Ni<Subscript>0.5</Subscript> exchanged with its adjacent Ni monolayers, leading to a buffer zone of Ni<Subscript>3</Subscript>Fe composition is found to be the most stable structural configuration. For this atomic arrangement we investigate the magnetic profile and the resulting interlayer exchange coupling between the Ni slabs for Fe spacer thickness of 0 to 4 monolayers. Copyright EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2006