We use polarized neutron reflectivity to study the evolution of the magnetization profile during the hysteresis of FeCoV (20 nm)/NiO (t NiO ) /FeCoV (20 nm) trilayers. For small t NiO , we find that the magnetization in the two ferromagnetic layers remains parallel, indicating a strong exchange coupling across the anti-ferromagnetic NiO layer. Beyond a film thickness t NiO = 40 nm, the observed step in the hysteresis is seen to correspond to an antiparallel orientation of the two ferromagnetic layers. Since this length scale agrees with the domain wall width of NiO, our results suggest that the interlayer exchange coupling involves a partial domain wall formation in the antiferromagnetic layer.     «

We use polarized neutron reflectivity to study the evolution of the magnetization profile during the hysteresis of FeCoV (20 nm)/NiO (t NiO ) /FeCoV (20 nm) trilayers. For small t NiO , we find that the magnetization in the two ferromagnetic layers remains parallel, indicating a strong exchange coupling across the anti-ferromagnetic NiO layer. Beyond a film thickness t NiO = 40 nm, the observed step in the hysteresis is seen to correspond to an antiparallel orientation of the two ferromagnetic l...     »