Mechanical Properties of Graphene Nanowiggles

TL;DR

This study uses atomistic simulations to explore how the topology of graphene nanowiggles influences their fracture behavior, revealing unique failure patterns and the formation of atomic chains during rupture.

Contribution

It provides novel insights into the mechanical properties and fracture mechanisms of graphene nanowiggles, highlighting the impact of nanoribbon topology on failure behavior.

Findings

Narrow nanoribbons exhibit higher failure strains.

Fracture patterns depend on nanoribbon topology.

Linear atomic chains form during rupture.

Abstract

In this work we have investigated the mechanical properties and fracture patterns of some graphene nanowiggles (GNWs). Graphene nanoribbons are finite graphene segments with a large aspect ratio, while GNWs are nonaligned periodic repetitions of graphene nanoribbons. We have carried out fully atomistic molecular dynamics simulations using a reactive force field (ReaxFF), as implemented in the LAMPPS (Large-scale Atomic/Molecular Massively Parallel Simulator) code. Our results showed that the GNW fracture patterns are strongly dependent on the nanoribbon topology and present an interesting behavior, since some narrow sheets have larger ultimate failure strain values. This can be explained by the fact that narrow nanoribbons have more angular freedom when compared to wider ones, which can create a more efficient way to accumulate and to dissipate strain/stress. We have also observed the formation of linear atomic chains (LACs) and some structural defect reconstructions during the material rupture. The reported graphene failure patterns, where zigzag/armchair edge terminated graphene structures are fractured along armchair/zigzag lines, were not observed in the GNW analyzed cases.