Graphitization of small diamond cluster — Molecular dynamics simulation

Molecular dynamics simulation was used to study graphitization process of a small diamond cluster at 1200, 1500, and 1800 K. The cluster was in the shape of a sphere of about 3 nm in diameter, and interaction between carbon atoms was described by the reactive bond order potential. Results obtained for 1500 K showed transformation of diamond nanoparticle into a carbon onion with diamond-like core and graphite layers in its outer shell. At 1800 K the process was faster and graphitization more effective. The whole final cluster was basically comprised of the onion structure, but it was irregular and separation between layers ranged from 0.2 to 0.3 nm.