Ferromagnetic Multipods Fabricated by Solution Phase Synthesis and Hydrogen Reduction

A simple approach combining pyrolysis and hydrogen reduction is formulated for making ferromagnetic-branched nanostructures called Co multipods. The CoO multipods (branched nanostructures) were produced through the pyrolysis of cobalt-oleate in octadecane at 280degC with the presence of oleic acid under the protection of pure nitrogen. The angles between the nearest arms are 90deg. After the reduction of the branched CoO nanostructures in flowing hydrogen gas in a tubular oven at 290degC, the CoO is reduced to pure cobalt with hexagonal crystal structure and the branched shapes are retained. Anisotropic magnetic properties were found for cobalt multipods on silicon substrates