Formation and Classification of Amorphous Carbon by Molecular Dynamics Simulation

TL;DR

This paper uses molecular dynamics simulations with a new potential model to investigate the formation mechanisms of amorphous carbon, successfully replicating transitions from graphite to diamond and the deposition of sp3-rich amorphous carbon.

Contribution

A novel potential model based on electron distribution was developed, enabling accurate simulation of amorphous carbon formation and phase transitions.

Findings

Simulation demonstrated graphite to diamond transition at 15 GPa

Successfully modeled deposition of sp3-rich amorphous carbon

Identified limitations of previous empirical potentials

Abstract

By using molecular dynamics simulation, formation mechanisms of amorphous carbon in particular sp${}^3$ rich structure was researched. The problem that reactive empirical bond order potential cannot represent amorphous carbon properly was cleared in the transition process from graphite to diamond by high pressure and the deposition process of amorphous carbon thin films. Moreover, the new potential model which is based on electron distribution simplified as a point charge was developed by using downfolding method. As a result, the molecular dynamics simulation with the new potential could demonstrate the transition from graphite to diamond at the pressure of 15 GPa corresponding to experiment and the deposition of sp${}^3$ rich amorphous carbon.