The computational study of initial temperature/pressure and atomic doping effects on the growth of crack in graphene nanostructure: Molecular dynamics approach

Abstract

Graphene is a two-dimensional material with excellent mechanical, electrical, and thermal properties made up of single layers of carbon atoms. Despite the fact that graphene is an emerging material, nowadays graphene has become the leader of the nano field, and with the discovery of its various properties, a tremendous transformation is taking place in nano science. In this study, the molecular dynamics method was used to examine the mechanical characteristics of graphene nanosheets. To achieve this, zig-zag and armchair-shaped graphene nanosheet samples were first simulated. In the second step of this research, by adding boron and nitrogen impurities inside the nanosheet structure, the growth of cracks in these structures was studied, and the effect of factors, such as temperature, pressure, and adding impurity atoms, such as nitrogen and boron were evaluated. In graphene nanosheets with zig-zag and armchair structures, the results demonstrate that the greatest fracture lengths were 28.91 Å and 23.6 Å, respectively. The crack length increased from 23.60 Å to 30.68 Å by increasing the temperature from 300 to 400 K. From 0 bar to 1 bar of pressure, the crack length went from 23.60 Å to 29.01 Å. The type of plates affected the mechanical properties in nanosheets, and nanosheets with armchair edges had better mechanical properties. Finally, the effect of impurities on graphene nanosheets was investigated. The simulations showed improved mechanical properties and resistance to crack growth in the presence of boron, nitrogen, or a combination of these atoms.