Magnetic moments in Fe–Co/Pt superlattices

The element specific spin and orbital moments for Fe and Co in Fe40Co60/PtFe40Co60/Pt (0 0 1) superlattices, with layer thicknesses dFeCo=4–10ML and dPt=8ML, have been studied by X-ray magnetic circular dichroism with focus on the interfacial magnetic moments of the Fe40Co60Fe40Co60 layers. The spin moments of Fe and Co showed the same relative decrease at the interfaces with respect to the bulk alloy. The change at the interface was found to be -0.9(1)-0.9(1) of the bulk alloy spin moment. The orbital moment for Fe also decreased at the interfaces, whereas the Co orbital moment did not show any appreciable change at the interfaces. In addition, SQUID measurements of the total magnetization allowed the extraction of the induced Pt magnetic moment, which was found to be 0.6(3)μB/atom and is discussed with respect to previous studies.