Atomic-scale defects restricting structural superlubricity: Ab initio study study on the example of the twisted graphene bilayer
| Autor: | Andrey M. Popov, Irina V. Lebedeva, Andrey A. Knizhnik, Alexander S. Minkin |
|---|---|
| Přispěvatelé: | Russian Foundation for Basic Research, European Commission |
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Friction Superlubricity FOS: Physical sciences 02 engineering and technology 01 natural sciences law.invention First-principles calculations symbols.namesake law Vacancy defect 0103 physical sciences Mesoscale and Nanoscale Physics (cond-mat.mes-hall) Physics::Atomic and Molecular Clusters 010306 general physics Condensed Matter - Materials Science Condensed matter physics Condensed Matter - Mesoscale and Nanoscale Physics Graphene Bilayer 2-dimensional systems Materials Science (cond-mat.mtrl-sci) 021001 nanoscience & nanotechnology Surface & interfacial phenomena Potential energy surface Density functional theory symbols van der Waals force 0210 nano-technology Bilayer graphene |
| Zdroj: | Phys. Rev. B Digital.CSIC. Repositorio Institucional del CSIC instname |
| ISSN: | 2469-9969 |
| DOI: | 10.1103/physrevb.104.075444 |
| Popis: | The potential energy surface (PES) of interlayer interaction of twisted bilayer graphene with vacancies in one of the layers is investigated via density functional theory (DFT) calculations with van der Waals corrections. These calculations give a non-negligible magnitude of PES corrugation of 28 meV per vacancy and barriers for relative sliding of the layers of 7 - 8 meV per vacancy for the moir\'e pattern with coprime indices (2,1) (twist angle 21.8$^\circ$). At the same time, using the semiempirical potential fitted to the DFT results, we confirm that twisted bilayer graphene without defects exhibits superlubricity for the same moir\'e pattern and the magnitude of PES corrugation for the infinite bilayer is below the calculation accuracy. Our results imply that atomic-scale defects restrict the superlubricity of 2D layers and can determine static and dynamic tribological properties of these layers in a superlubric state. We also analyze computationally cheap approaches that can be used for modeling of tribological behavior of large-scale systems with defects. The adequacy of using state-of-the-art semiempirical potentials for interlayer interaction and approximations based on the first spatial Fourier harmonics for the description of interaction between graphene layers with defects is discussed. Comment: 11 pages, 4 figures |
| Databáze: | OpenAIRE |
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