Anomalous magnetic and magnetotransport properties in nanostructured networks of Co/NiO/Fe trilayers

The formation of an interconnected nanostructured network of Co/NiO/Fe trilayers on anodic aluminum oxide (AAO) template strongly affects the interfacial exchange coupling between antiferromagnetic and ferromagnetic layers in comparison with continuous films of trilayers on silicon substrate. Anomalous magnetic and magnetotransport properties, in particular a positive magnetoresistance (MR), are observed for the network on AAO, but a negative MR is found for the film on Si. The non-monotonic temperature dependence of the resistivity at low temperatures of the network on AAO can be qualitatively understood in terms of a two-current model.

► The anodic aluminum oxide template affects the interfacial exchange coupling.
► A positive and negative magnetoresistance is observed for different samples.
► The non-monotonic temperature dependence of the resistivity can be understood.