Curvature effects on mechanical and electrical properties of graphene: A study using first principle and molecular dynamics

Since the discovery of graphene by Geim and Novoselov, the material has been the focal point of a large body of research. The material exhibits properties unlike any other and the areas of investigation and the amount of knowledge about the material, could be argued, are only in its infancy. Studying such a material is often times more practical if not the only means by way of computational analysis. Here two such methods, an ab initio technique using DFT - LDA calculations and a molecular dynamics approach are used to gain insight into the materials behavior. The avenue of interest is the study of the effects that large curvatures may play on the mechanical and electrical properties of a graphene nanoribbon. Two structures that had the proper curvature characteristics and were energetically stable were found and investigated using the two techniques listed. The total energy for the structures was decomposed into the binding and the strain energy of the graphene nanoribbon. The strain energy was shown to exhibit a quadratic dependence on curvature and this mimicked what has been published previously. The binding energy however showed an interesting "bi-phasic" nature in which there were two different progressions of a quadratic dependence. The mechanical behavior of the ribbon was determined and showed that the ribbon itself exhibited very little disturbance due to the curvature as the strain and stress values were quite minimal. Finally, the electrical properties proved to incite further questions with one structure conforming to the known behavior while the other may prove to be entirely new with further research.