In–Ni microballs catalyzed growth of dense and highly aligned silica nanowires

A new method has been developed to produce dense and highly aligned silica nanowires. Subliming In2O3 powder to a Si wafer coated with nickel (Ni) nanoparticles under N2/NH3, highly aligned nanowires were produced in large quantities. The nanowires are of uniform diameters (10–20 nm) and lengths (5–20 μm). The aligned nanowires are also often self-assembled into a variety of elegant architectures. The discussion on the growth mechanism suggests that the nanowires were initiated from microballs (1–20 μm in diameter) of In–Ni alloys. The alignment of the nanowires was due to an overcrowding effect.