Molecular Dynamics Simulation of Fracture Strength and Morphology of Defective Graphene

Abstract

Different types of defects can be introduced into graphene during material synthesis, and significantly influence the properties of graphene. In this work, we investigated the effects of structural defects, edge functionalisation and reconstruction on the fracture strength and morphology of graphene by molecular dynamics simulations. The minimum energy path analysis was conducted to investigate the formation of Stone-Wales defects. We also employed out-of-plane perturbation and energy minimization principle to study the possible morphology of graphene nanoribbons with edge-termination. Our numerical results show that the fracture strength of graphene is dependent on defects and environmental temperature. However, pre-existing defects may be healed, resulting in strength recovery. Edge functionalization can induce compressive stress and ripples in the edge areas of graphene nanoribbons. On the other hand, edge reconstruction contributed to the tensile stress and curved shape in the graphene nanoribbons.

Lithium concentration dependent structure and mechanics of amorphous silicon

“…39,40 All simulations were performed using LAMMPS software, 41 which has been used for simulating mechanical properties of nanomaterials in our previous studies. [42][43][44] Atomic structure analysis and visualization were carried out using OVITO 45 and VMD 46 postprocessing tools.…”

Atomistic investigation into the mechanical behaviour of crystalline and amorphous TiO2 nanotubes

“…Note that the fracture strength and yield stress obtained from MD simulations are generally higher than those from experiments. 63 This is attributed to the large number of structural defects in TiO 2 nanotubes formed during synthesis process.…”

“…With increasing the tensile loading, the C-C bond breaking triggers crack propagation and fracture. 63,64 The structural defects inside may act as the sites of stress concentration and initiate the bond breaking.…”

Role of sulphur atoms on stress relaxation and crack propagation in monolayer MoS2

“…Since devices based on atomically thin films experience mechanical strain or stress during either fabrication or from intentional strain engineering [6], their mechanical properties are important from reliability perspective. As the first member of the family, graphene has been studied extensively for its mechanical properties [7][8][9][10][11][12][13]. However, atomic structures of graphene and MoS 2 are different; MoS 2 consists of equivalent three layers of S-Mo-S atoms while graphene is a single layer of C atoms only.…”