Energetics and structure of grain boundary triple junctions in graphene
journal contributionposted on 05.09.2017, 11:13 by Petri Hirvonen, Zheyong Fan, Mikko M. Ervasti, Ari Harju, Ken R. Elder, Tapio Ala-NissilaTapio Ala-Nissila
© 2017 The Author(s). Grain boundary triple junctions are a key structural element in polycrystalline materials. They are involved in the formation of microstructures and can influence the mechanical and electronic properties of materials. In this work we study the structure and energetics of triple junctions in graphene using a multiscale modelling approach based on combining the phase field crystal approach with classical molecular dynamics simulations and quantum-mechanical density functional theory calculations. We focus on the atomic structure and formation energy of the triple junctions as a function of the misorientation between the adjacent grains. We find that the triple junctions in graphene consist mostly of five-fold and seven-fold carbon rings. Most importantly, in addition to positive triple junction formation energies we also find a significant number of orientations for which the formation energy is negative.
This research has been supported in part by the Academy of Finland through its Centres of Excellence Program (projects nos 251748 and 284621) as well as projects 263416 and 286279. P.H. acknowledges financial support from the Foundation for Aalto University Science and Technology, and from the Vilho, Yrjo and Kalle Vaisala Foundation of the Finnish Academy of Science and Letters. K.R.E. acknowledges financial support from the National Science Foundation under Grant No. DMR-1506634
- Mathematical Sciences