The stability of graphene based M\"obius strip with vacancy at high temperature

TL;DR

This study uses DFT and MD simulations to analyze the stability and melting behavior of vacancy defects in graphene-based Möbius strips at high temperatures, revealing defect transformations and a melting point of around 2750 K.

Contribution

It provides new insights into the defect configurations and thermal stability of graphene Möbius strips, including the transformation of vacancy types and their melting temperature.

Findings

5566-type vacancy is unstable at room temperature and transforms into 59-type

Melting temperature of graphene Möbius strips is approximately 2750 K

The 5566-type vacancy is most stable in twisted areas at static conditions

Abstract

By using the density functional theory (DFT) combined with the molecular dynamics (MD) simulations, structural and electronic properties of mono-vacancy (MV) defect in M\"obius strip formed from graphene are investigated. Two kinds of MV are observed depending on the local structures around defects. At static condition, in the curved areas of M\"obius strip, MV has the configuration of one pentagon and one nonagon ring (59-type), which is similar to that of carbon nanotubes and graphene. the most stable MV appear in the twisted areas and has a profile of two pentagon and two hexagon rings (5566-type) with one sp3 hybridized carbon at the central site. While DFT-MD simulations prove that the 5566-type MV is an unstable configuration at room temperature and will transform into a 59-type MV. Additionally, the melting behavior of graphene based M\"obius strips are investigated through empirical potential MD simulations, and we find that their melting temperature is about 2750 K, which is lower than that of carbon nanotubes and graphene.