title: Toughness and strength of nanocrystalline graphene.
abstract: Pristine monocrystalline graphene is claimed to be the strongest material known with remarkable mechanical and electrical properties. However, graphene made with scalable fabrication techniques is polycrystalline and contains inherent nanoscale line and point defects--grain boundaries and grain-boundary triple junctions--that lead to significant statistical fluctuations in toughness and strength. These fluctuations become particularly pronounced for nanocrystalline graphene where the density of defects is high. Here we use large-scale simulation and continuum modelling to show that the statistical variation in toughness and strength can be understood with 'weakest-link' statistics. We develop the first statistical theory of toughness in polycrystalline graphene, and elucidate the nanoscale origins of the grain-size dependence of its strength and toughness. Our results should lead to more reliable graphene device design, and provide a framework to interpret experimental results in a broad class of two-dimensional materials.
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.|Department of Materials Science &Engineering, University of California, 324 Hearst Memorial Mining Building, MC 1760, Berkeley, California 94720, USA.|Miller Institute for Basic Research in Science, Berkeley, California 94720, USA.
authors.forename: Ashivni
authors.initials: A
authors.lastname: Shekhawat
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.|Department of Materials Science &Engineering, University of California, 324 Hearst Memorial Mining Building, MC 1760, Berkeley, California 94720, USA.
authors.forename: Robert O
authors.initials: RO
authors.lastname: Ritchie
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