Molecular Dynamics Observation of Iron–Carbon precursors of Carbon Nanotube and Development of Iron–Carbon Potential

Abstract

Abstract.We have focused on the growth process of metal and carbon mixed clusters that are precursors for carbon nanotubes. The molecular dynamics method using the Brenner potential was employed for modeling carbon-carbon interactions as well as carbon-iron interactions. As for carbon-iron interactions, the parameters were derived using DFT calculation. The Finnis-Sinclair potential was employed for irons. In order to observe the deposition process of carbon atoms, we adjusted the potential parameters to reproduce the bulk melting points of graphite, iron, and cementite, which was a model material of ironcarbon composite. We observed the initial growth process by preparing iron-carbon mixed clusters (approximately 200 iron atoms and 70 carbon atoms) as precursor clusters. Additional carbon atoms were then gradually supplied to this mixture at 1000 K and 1200 K. Consequently, the graphite structure was formed on the mixture surface, but at some phases, the cap structure was observed at 1200 K.

Influence of tip adhesion on nanoindentation and scratching

“…The study of the interaction of Fe and C has a long tradition, and a multitude of interaction potentials have been developed to describe the interaction of Fe and C atoms in bulk materials. We mention pair potentials [19,20] and many-body potentials [9,[21][22][23][24][25][26][27][28] to describe the interaction of interstitial C in Fe, potentials for carbides [24,[26][27][28][29] and for mixed Fe-C clusters [30]. In the present study, however, we will base our description on a simple pair potential approach.…”