title: Inverse pseudo Hall-Petch relation in polycrystalline graphene.
abstract: Understanding the grain size-dependent failure behavior of polycrystalline graphene is important for its applications both structurally and functionally. Here we perform molecular dynamics simulations to study the failure behavior of polycrystalline graphene by varying both grain size and distribution. We show that polycrystalline graphene fails in a brittle mode and grain boundary junctions serve as the crack nucleation sites. We also show that its breaking strength and average grain size follow an inverse pseudo Hall-Petch relation, in agreement with experimental measurements. Further, we find that this inverse pseudo Hall-Petch relation can be naturally rationalized by the weakest-link model, which describes the failure behavior of brittle materials. Our present work reveals insights into controlling the mechanical properties of polycrystalline graphene and provides guidelines for the applications of polycrystalline graphene in flexible electronics and nano-electronic-mechanical devices.
authors.affiliation: International Center for Applied Mechanics, State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi'an Jiaotong University, Xi'an 710049, China.
authors.forename: Z D
authors.initials: ZD
authors.lastname: Sha
authors.affiliation: Institute of High Performance Computing, A*Star, 138632, Singapore.
authors.forename: S S
authors.initials: SS
authors.lastname: Quek
authors.affiliation: Institute of High Performance Computing, A*Star, 138632, Singapore.
authors.forename: Q X
authors.initials: QX
authors.lastname: Pei
authors.affiliation: International Center for Applied Mechanics, State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi'an Jiaotong University, Xi'an 710049, China.
authors.forename: Z S
authors.initials: ZS
authors.lastname: Liu
authors.affiliation: State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
authors.forename: T J
authors.initials: TJ
authors.lastname: Wang
authors.affiliation: Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: V B
authors.initials: VB
authors.lastname: Shenoy
authors.affiliation: Institute of High Performance Computing, A*Star, 138632, Singapore.
authors.forename: Y W
authors.initials: YW
authors.lastname: Zhang
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