Related Experiment Video
Updated: Mar 28, 2026
08:03
Advanced Self-Healing Asphalt Reinforced by Graphene Structures: An Atomistic Insight
Published on: May 31, 2022
5.7K
Dislocation Shielding of a Nanocrack in Graphene: Atomistic Simulations and Continuum Modeling
Fanchao Meng1, Cheng Chen1, Jun Song1
1Department of Mining and Materials Engineering, McGill University , Montréal, Québec H3A 0C5, Canada.
The Journal of Physical Chemistry Letters
|January 2, 2016
Summary
Dislocations shield nanocracks in graphene by altering stress intensity. The shielding effect depends on the crack-dislocation distance, with distinct behaviors near and far from the crack tip.
Area of Science:
- Materials Science
- Solid Mechanics
- Nanotechnology
Background:
- Graphene's unique properties make it suitable for advanced applications.
- Understanding crack propagation is crucial for material reliability.
- Dislocations can influence crack behavior in materials.
Purpose of the Study:
- To investigate dislocation shielding effects on nanocracks in graphene.
- To analyze the relationship between crack-dislocation separation and shielding.
- To provide insights into defect engineering in graphene.
Main Methods:
- Combined atomistic simulations and continuum modeling.
- Constructed various crack-dislocation configurations.
- Examined shielding effects on threshold stress intensity for crack propagation.
Main Results:
- Achieved excellent agreement between simulation results and linear-elastic fracture mechanics (LEFM) predictions.
- Observed two distinct shielding dependences on crack-dislocation separation (rR).
- Identified 1/rR^1/2 scaling for near-tip interactions and 1/rR scaling for far-field interactions.
Conclusions:
- The far-field 1/rR scaling is a direct manifestation of graphene's dislocation stress field.
- This study offers a systematic analysis of nanoscale crack-dislocation interactions in graphene.
- Findings provide valuable information for defect engineering strategies in graphene.
Related Concept Videos
01:14Diamagnetic Shielding of Nuclei: Local Diamagnetic Current
1.6K
An applied magnetic field causes the electrons present in the molecule to circulate, setting up a local diamagnetic current within the molecule. The local diamagnetic current arising from circulating sigma-bonding electrons induces a magnetic field, Blocal that opposes the applied magnetic field, B0. The effective magnetic field experienced by these nuclei is given by the difference between the applied and local magnetic fields in a phenomenon called local diamagnetic shielding. Essentially,...
1.6K
01:26Imperfections in Crystal Structure: Stoichiometric Point Defects
85
Schottky defects arise when some lattice points in a crystal, such as those in NaCl, remain unoccupied, creating lattice vacancies without disturbing the overall electrical neutrality of the crystal. This defect is common in ionic crystals where the positive and negative ions are similar in size, as seen in sodium chloride and cesium chloride. The presence of Schottky defects enables the crystal to conduct electricity to a small extent through an ionic mechanism. Electric fields cause nearby...
85
01:27π Electron Effects on Chemical Shift: Overview
1.9K
An applied magnetic field causes loosely bound π-electrons in organic molecules to circulate, producing a local or induced diamagnetic field over a large spatial volume. As the molecules tumble in solution, the field generated by π-electrons in spherical substituents results in a zero net field. However, the net field generated by π-electrons in non-spherical substituents is not zero. The effect of this induced field depends on the orientation of the molecule with respect to B0,...
1.9K