Melting of graphene: from two to one dimension

TL;DR

This study uses atomistic simulations to explore how graphene melts at high temperatures, revealing a process involving defect clustering, chain formation, and a molten state of entangled chains at around 4900 K.

Contribution

It provides detailed atomistic insights into the melting process of graphene, including defect dynamics and the nature of the molten state, which were previously not well understood.

Findings

Melting involves defect clustering and chain formation.

The molten state is a network of entangled carbon chains.

Estimated melting temperature is about 4900 K.

Abstract

The high temperature behaviour of graphene is studied by atomistic simulations based on an accurate interatomic potential for carbon. We find that clustering of Stone-Wales defects and formation of octagons are the first steps in the process of melting which proceeds via the formation of carbon chains. The molten state forms a three-dimensional network of entangled chains rather than a simple liquid. The melting temperature estimated from the two-dimensional Lindemann criterion and from extrapolation of our simulation for different heating rates is about 4900 K.