Electrochemically grown metallic nanocomb structures on nanoporous alumina templates

Electrochemical growth of metallic nanocomb structures on anodized alumina templates is described. Nanocombs originate from the orderly growth and merger of very thin (d = 15 -/+ 5 nm) metallic nanowires which do not completely fill much larger pores (d similar to 100 nm) in the alumina template (t <= 3 mu m). Instead, the nanowires prefer growing along the inner corners of the hexagonal pores, coalescing into a highly ordered structure as they emerge, resulting a metallic form reminiscent of the topology of the original template. We disclose here the typical processing conditions and the microstructure of this previously unknown material as observed with a scanning electron microscope (SEM) and energy dispersive x-ray (EDX) spectroscopy. It is shown that Au nanocombs have an anomalous EDX spectra and can emit electrons at a field of similar to 1 kV/cm. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3596432]