Volume 17, Issue 52 2104238
Research Article

Atomistic Mechanics of Torn Back Folded Edges of Triangular Voids in Monolayer WS2

Gyeong Hee Ryu

Corresponding Author

Gyeong Hee Ryu

School of Materials Science and Engineering, Gyeongsang National University, Jinju, 52828 Republic of Korea

E-mail: [email protected]; [email protected]; [email protected]

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Gang Seob Jung

Corresponding Author

Gang Seob Jung

Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 USA

E-mail: [email protected]; [email protected]; [email protected]

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Hyoju Park

Hyoju Park

Materials Graduate Program, Texas Materials Institute, The University of Texas at Austin, 204 East Dean Keeton Street, Austin, TX, 78712 USA

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Ren-Jie Chang

Ren-Jie Chang

Department of Materials, University of Oxford, 16 Parks Road, Oxford, OX1 3PH UK

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Jamie H. Warner

Corresponding Author

Jamie H. Warner

Walker Department of Mechanical Engineering, The University of Texas at Austin, 204 East Dean Keeton Street, Austin, TX, 78712 USA

E-mail: [email protected]; [email protected]; [email protected]

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First published: 27 October 2021

Abstract

Triangular nanovoids in 2D materials transition metal dichalcogenides have vertex points that cause stress concentration and lead to sharp crack propagation and failure. Here, the atomistic mechanics of back folding around triangular nanovoids in monolayer WS2 sheets is examined. Combining atomic-resolution images from annular dark-field scanning transmission electron microscopy with reactive molecular modelling, it is revealed that the folding edge formation has statistical preferences under geometric conditions based on the orientation mismatch. It is further investigated how loading directions and strong interlayer friction, interplay with WS2 lattice's crack preference, govern the deformation and fracture pattern around folding edges. These results provide fundamental insights into the combination of fracture and folding in flexible monolayer crystals and the resultant Moiré lattices.

Conflict of Interest

The authors declare no conflict of interest.

Data Availability Statement

Research data are not shared.

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