Atomistic simulations of pristine and defective hexagonal BN and SiC sheets under uniaxial tension
MQ Le and DT Nguyen, MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, 615, 481-488 (2014).
The uniaxial tensile mechanical properties of pristine and defective hexagonal boron nitride (BN) and silicon carbide (SiC) sheets are investigated through a molecular dynamics finite element method with Tersoff and Tersoff-like potentials. 2-Atom vacancy and 2 types of Stone-Wales defects are considered. It is found that uniaxial tensile stress-strain curves of defective and pristine sheets are almost identical up to fracture points. A centered single defect reduces significantly fracture stress and fracture strain from those of the corresponding pristine sheet. In contrast, Young's modulus is nearly unchanged by a single defect. One 2-atom vacancy in the sheet's center reduces 15-18% and 16-25% in fracture stress, and 32-34% and 32-48% in fracture strain of BN and SiC sheets, respectively. Reduction in fracture properties depends on the tensile direction as well as the orientation of Stone-Wales defects. (C) 2014 Elsevier B.V. All rights reserved.
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