Dramatic enhancement of interlayer exchange coupling and giant magnetoresistance in Ni₈₁Fe₁₉/Cu multilayers by addition of thin Co interface layers

The giant magnetoresistance (MR) of Ni81Fe19/Cu multilayers is dramatically enhanced by inserting thin Co layers at each Ni 81Fe19/Cu interface, unambiguously demonstrating the predominant interfacial origin of the giant MR effect. Similarly the long-range oscillatory MR and interlayer exchange coupling only present in magnetron sputtered Ni81Fe19/Cu multilayers at low temperatures is restored at higher temperatures by the addition of thin Co interface layers. Multilayered structures comprised of Co/Ni81Fe19/Co/Cu exhibit MR of more than 17% for field changes of ±100 Oe at room temperature.