Shear-coupling of graphene grain boundaries: Elementary mechanisms, effects of topology, and role of buckling

Emil Annevelink, Brian Xu, Harley T. Johnson, Elif Ertekin

Research output: Contribution to journalArticlepeer-review


Engineering grain boundary structure is a promising method for rational control of the microstructure and mechanical properties of two-dimensional materials. In bulk materials, shear stresses can drive grain boundary migration through the dislocations in grain boundaries. However, while shear coupling of grain boundaries has been studied in bulk materials like nanocrystalline copper, its translation to two-dimensional materials where out-of-plane deformation can relieve in-plane shear is not yet established. We investigate how the low flexural rigidity of graphene effects shear coupled grain boundary motion using atomic scale simulations of flat and buckled grain boundaries. We define the coupling shear strain as the strain at which a grain boundary has advanced by one Burgers vector and is at equilibrium and the critical shear strain as the strain at which migration of the first dislocation in the grain boundary becomes thermodynamically favorable. We show that the out-of-plane deformation does not influence the coupling shear strain and is governed only by the grain boundary topology. While the critical shear strain is altered somewhat by the low flexural rigidity due to buckling induced softening, it is also still dominated by the grain boundary topology. Our atomic scale results are synthesized into two models that predict the coupling and critical shears.

Original languageEnglish (US)
Article number118488
JournalActa Materialia
StatePublished - Jan 1 2023


  • Disconnections
  • Grain boundaries
  • Graphene
  • Out-of-plane deformations
  • Shear-coupling

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Polymers and Plastics
  • Metals and Alloys


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