Mapping Nanoscale Electrostatic Field Fluctuations around Graphene Dislocation Cores Using Four-Dimensional Scanning Transmission Electron Microscopy (4D-STEM).

Autor:	Coupin MJ; Materials Science and Engineering Program, Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, United States., Wen Y; Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom., Lee S; Department of Materials Science & Engineering, Seoul National University, Seoul 08826, Republic of Korea.; Research Institute of Advanced Materials, Seoul National University, Seoul 08826, Republic of Korea., Saxena A; Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States.; Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, Texas 78712, United States., Ophus C; National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, One Cyclotron Road, Building 67, Berkeley, California 94720, United States., Allen CS; Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom.; Electron Physical Science Imaging Centre, Diamond Light Source Ltd., Didcot OX11 0DE, U.K., Kirkland AI; Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom.; Electron Physical Science Imaging Centre, Diamond Light Source Ltd., Didcot OX11 0DE, U.K.; Rosalind Franklin Institute, Harwell Science and Innovation Campus, Didcot OX11 0QX, U.K., Aluru NR; Materials Science and Engineering Program, Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, United States.; Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States.; Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, Texas 78712, United States., Lee GD; Department of Materials Science & Engineering, Seoul National University, Seoul 08826, Republic of Korea.; Research Institute of Advanced Materials, Seoul National University, Seoul 08826, Republic of Korea., Warner JH; Materials Science and Engineering Program, Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, United States.; Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States.
Jazyk:	angličtina
Zdroj:	Nano letters [Nano Lett] 2023 Aug 09; Vol. 23 (15), pp. 6807-6814. Date of Electronic Publication: 2023 Jul 24.
DOI:	10.1021/acs.nanolett.3c00328
Abstrakt:	Defects in crystalline lattices cause modulation of the atomic density, and this leads to variations in the associated electrostatics at the nanoscale. Mapping these spatially varying charge fluctuations using transmission electron microscopy has typically been challenging due to complicated contrast transfer inherent to conventional phase contrast imaging. To overcome this, we used four-dimensional scanning transmission electron microscopy (4D-STEM) to measure electrostatic fields near point dislocations in a monolayer. The asymmetry of the atomic density in a (1,0) edge dislocation core in graphene yields a local enhancement of the electric field in part of the dislocation core. Through experiment and simulation, the increased electric field magnitude is shown to arise from "long-range" interactions from beyond the nearest atomic neighbor. These results provide insights into the use of 4D-STEM to quantify electrostatics in thin materials and map out the lateral potential variations that are important for molecular and atomic bonding through Coulombic interactions.
Databáze:	MEDLINE
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