Controllable synthesis of ferromagnetic–antiferromagnetic core–shell NWs with tunable magnetic properties

Abstract

Several nanotechnology applications are based on the promising scheme of highly anisotropic magnetic nanomaterials. Using this idea, we investigated the structure, magnetic properties, and interfacial exchange anisotropy effects of the Ni/Cr₂O₃ and Fe/Cr₂O₃ core–shell nanowires (NWs) geometry. A template-based strategy was developed to synthesize Ni (Fe)–Cr₂O₃ core–shell NWs, which combines a wet-chemical route and electrodeposition within the nanopores of the membranes. Structural determination in correlation with magnetic testing shows that the crystalline Cr₂O₃-nanoshells (NSs) cause an enhanced exchange bias, providing an extra source of anisotropy that leads to their magnetic stability. This core–shell NWs geometry, with enhanced anisotropy, should, therefore, motivate further study related to the applicability of anisotropic nanostructures. Our design opens a new pathway to obtain optimized heterostructured nanomaterials exhibiting tunable magnetic properties.