Gold bead-strings in silica nanowires: a simple diffusion model.
Silica nanowires grown from gold droplets deposited on the surface of a silicon crystal sometimes develop within them a regular series of gold beads distributed along the wire axis in what is often called either a bead-string or a pea-pod structure. This is generally attributed to a 'Rayleigh instability' driven by the surface free energy of the included gold core. Here a new model is proposed in which quasi-conical gold inclusions are developed by the diffusion-limited growth process and are subsequently modified to spherical shape by another diffusion process that is driven by surface free energy. This model provides a possible basis for detailed numerical calculations.
Research School of Physics and Engineering, Australian National University, Canberra 0200, Australia. neville.fletcher@anu.edu.au
N H
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Fletcher
R G
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Elliman
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Kim
D003198:Computer Simulation; D004058:Diffusion; D006046:Gold / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties
D046911:Macromolecular Substances; D006046:Gold; D012822:Silicon Dioxide