The diffusion of copper nanoclusters in carbon nanotubes was investigated using a classical molecular dynamics simulation and three empirical potential functions. The results indicated a growth mechanism of the copper-filled ultra-thin carbon nanotubes: the copper nanoclusters inserted into carbon nanotubes swiftly migrated along the tube axis, and then the copper nanowires 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 nanocluster in the carbon nanotube obeyed the Arrhenius relationship.

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