Fe and Co Nanowires and Nanotubes Synthesized by Template Electrodeposition

Co and Fe nanowires and/or nanotubes are electrochemically synthesized through nanoporous membranes. By combining high-resolution transmission electron microscopy (HRTEM), electron energy loss spectroscopy (EELS), and energy filtered TEM techniques, their structural and crystallographic characteristics are precisely determined. The synthesis was shown to produce cigar-shaped single monocrystalline Co and Fe nanowires with a diameter of about 60 nm. All wires were surrounded by an epitaxial oxide layer (Co 3 O 4 or Fe 3 O 4 ) of roughly 10 nm. The Fe nanotubes were built up of Fe 3 O 4 nanocrystals. Electron diffraction showed that all nanocrystals had a common crystallographic axis, creating a pseudomonocrystalline wall in the nanotubes.