Magnetite (Fe3O4) core-shell nanowires:: Synthesis and magnetoresistance

High quality MgO/Fe3O4 core-shell nanowires have been successfully synthesized by depositing an epitaxial shell of Fe3O4 onto single crystal MgO nanowires. The material composition and stoichoimetric ratio have been carefully examined and confirmed with a variety of characterization techniques. These novel structures have rendered unique opportunities to investigate the transport behavior and spintronic property of Fe3O4 in its one-dimensional form. Room-temperature magnetoresistance of similar to1.2% was observed in the as-synthesized nanowires under a magnetic field of B = 1.8 T, which has been attributed to the tunneling of spin-polarized electrons across the anti-phase boundaries.