Nucleation and reshaping thermodynamics of Ni as catalyst of carbon nanotubes

A quantitative model describing the nucleation, energy, and diffusion restraints in reshaping of Ni nanoparticles as a catalyst of carbon nanotubes is developed by introducing the size-dependent thermodynamic quantities in the classical nucleation theory and the diffusion laws. The result from our model calculations is in good agreement with that of the latest time-resolved, high-resolution in situ transmission electron microscope observation. A new catalytic nanotube growth mechanism is proposed: the growth of a carbon nanotube coupled to the reshaping of the catalyst.