Hierarchal silica nanowire growth via single step annealing

Branched silica nanowires were grown on silicon substrates using a gold-catalyzed vapor-liquid-solid process in which the substrate was covered with a silicon capping layer. The reduced O₂ partial pressure due to the capping layer is shown to result in regions of frustrated nanowire growth. By comparing electron micrographs from different regions, a growth mechanism for the branched nanowires is proposed.