Growth, structure and luminescence properties of electrodeposited and post-oxidized Co oxide nanowires

We present a route for the synthesis of arrays of ordered metal oxide nanowires, using a combination of electrodeposition in polycarbonate templates and thermal annealing in oxygen atmosphere. Structural characterization shows that, after oxidation of Co nanowires, an array of Co3O4 polycrystalline nanowires is obtained. Magnetic measurements confirm that the wires are fully oxidized and that they are antiferromagnetic with a Nèel temperature slightly lower than that corresponding to bulk Co3O4. Cathodoluminescence spectra of the Co3O4 nanowires show an emission band peaked near 2.1 eV that can be attributed to the optical band gap of this material, as well as other emissions centered at lower energies which are strongly dependent on the crystal quality.