The diffusion of copper nanoclusters in carbon nanotubes was investigated using classical molecular dynamics simulations and three empirical potential functions. The results indicated a growth mechanism of copper-filled ultra-thin carbon nanotubes: the copper nanoclusters inserted into carbon nanotubes swiftly migrated along the tube axis, and copper nanowires then grew in the ultra-thin carbon nanotubes. Periodic energy barriers in the carbon nanotubes induced the directional movement of copper nanoclusters in the carbon nanotubes. The diffusion speeds of copper nanoclusters in the nanotubes obeyed an Arrhenius relationship.

Copper Nanocluster Diffusion in Carbon Nanotube. H.J.Hwang, O.K.Kwon, J.W.Kang: Solid State Communications, 2004, 129[11], 687-90