Small Si clusters on surfaces of carbon nanotubes

Structures of small Si clusters, Si-n, on surfaces of carbon nanotubes have been studied by molecular dynamics simulation. We show that the lowest-energy structures of Si-n are three-dimensional clusters rather than thin Si sheets covering the surface of a nanotube. As n increases from 10 to 30, Si-n undergoes structural transitions from a tentlike structure (with nanotube surface as its base) to a cagelike structure (without interior atoms) and further to a spherical compact structure (with interior atoms). Our results are different from the structures of small Si clusters found in a free space without Si-nanotube interaction. (c) 2006 American Institute of Physics.