Understanding the nucleation mechanisms of Carbon Nanotubes in catalytic Chemical Vapor Deposition

摘要

The nucleation of carbon caps on small nickel clusters is studied using atight binding model coupled to grand canonical Monte Carlo simulations. Ittakes place in a well defined carbon chemical potential range, when a criticalconcentration of surface carbon atoms is reached. The solubility of carbon inthe outermost Ni layers, that depends on the initial, crystalline ordisordered, state of the catalyst and on the thermodynamic conditions, istherefore a key quantity to control the nucleation.