Exchange coupling of Fe/NiO through nonmagnetic layer in NiO

The role of non-interfacial antiferromagnetic (AFM) layers is examined by propagating a probing layer through the AFM and measuring the resultant changes in H_EB using magneto-optical Kerr effect (MOKE) magnetometry. Two different types of samples were grown using magnetron sputtering system: type-I samples consists of 20 Å Ru/20 Å Fe/x Å NiO/150 Å Ag, and type-II samples consists of 20 Å Ru/20 Å Fe/x Å NiO/2.5 Å, 5.0 Å 7.5 Å MgO, Ag, Cu/500-x Å NiO/150 Å Ag, where x is from 0 Å to 210 Å. H_EB for type-I samples is long-range coupling from the point of view of the AFM and is consistent with a generalized Meiklejohn-Bean approach. In type-II samples, MgO layer decouples more the thin interfacial NiO from bottom NiO than other nonmagnetic layer. The decoupling of Ag is smallest.