title: Measurement of the cleavage energy of graphite.
abstract: The basal plane cleavage energy (CE) of graphite is a key material parameter for understanding many of the unusual properties of graphite, graphene and carbon nanotubes. Nonetheless, a wide range of values for the CE has been reported and no consensus has yet emerged. Here we report the first direct, accurate experimental measurement of the CE of graphite using a novel method based on the self-retraction phenomenon in graphite. The measured value, 0.37±0.01 J m(-2) for the incommensurate state of bicrystal graphite, is nearly invariant with respect to temperature (22 °C≤T≤198 °C) and bicrystal twist angle, and insensitive to impurities from the atmosphere. The CE for the ideal ABAB graphite stacking, 0.39±0.02 J m(-2), is calculated based on a combination of the measured CE and a theoretical calculation. These experimental measurements are also ideal for use in evaluating the efficacy of competing theoretical approaches.
authors: Department of Engineering Mechanics, Center for Nano and Micro Mechanics, Applied Mechanics Lab, Tsinghua University, Beijing 100084, China.
authors: Wen
authors: W
authors: Wang
authors: Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
authors: Shuyang
authors: S
authors: Dai
authors: Department of Engineering Mechanics, Center for Nano and Micro Mechanics, Applied Mechanics Lab, Tsinghua University, Beijing 100084, China.
authors: Xide
authors: X
authors: Li
authors: Department of Engineering Mechanics, Center for Nano and Micro Mechanics, Applied Mechanics Lab, Tsinghua University, Beijing 100084, China.
authors: Jiarui
authors: J
authors: Yang
authors: Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.|Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
authors: David J
authors: http://orcid.org/0000-0001-6038-020X
authors: DJ
authors: Srolovitz
authors: Department of Engineering Mechanics, Center for Nano and Micro Mechanics, Applied Mechanics Lab, Tsinghua University, Beijing 100084, China.|XIN Center, Tsinghua University, Beijing 100084, China.|State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China.
authors: Quanshui
authors: Q
authors: Zheng