Pseudo Hall-Petch strength reduction in polycrystalline graphene

Nano Lett. 2013 Apr 10;13(4):1829-33. doi: 10.1021/nl400542n. Epub 2013 Mar 25.


The fracture of polycrystalline graphene is explored by performing molecular dynamics simulations with realistic finite-grain-size models, emphasizing the role of grain boundary ends and junctions. The simulations reveal a ~50% or more strength reduction due to the presence of the network of boundaries between polygonal grains, with cracks preferentially starting at the junctions. With a larger grain size, a surprising systematic decrease of tensile strength and failure strain is observed, while the elastic modulus rises. The observed crack localization and strength behavior are well-explained by a dislocation-pileup model, reminiscent of the Hall-Petch effect but coming from different underlying physics.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Computer Simulation
  • Elastic Modulus
  • Graphite / chemistry*
  • Models, Chemical
  • Molecular Dynamics Simulation
  • Nanoparticles / chemistry*
  • Nanostructures
  • Particle Size*
  • Surface Properties


  • Graphite