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Updated: Jan 16, 2026
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Sample Preparation and Experimental Design for In Situ Multi-Beam Transmission Electron Microscopy Irradiation Experiments
Published on: June 27, 2022
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Collective Rotation Mode in Lattice Migration under Electron Irradiation
Jiajian Guan1,2, Wuxin Yang1, Richard F Webster3
1Department of Chemical and Materials Engineering, University of Auckland, Auckland 1010, New Zealand.
Nano Letters
|January 15, 2026
Summary
Nanoparticles rotate and merge due to transient thermal spikes from electron beams. This collective rotation mechanism, driven by asymmetric temperature gradients, explains nanocrystal migration and coalescence under irradiation.
Area of Science:
- Materials Science
- Nanotechnology
- Surface Science
Background:
- Atomic migration dynamics are key for nanomaterial synthesis and modification.
- A universal nanoscale rotation mode is observed during annealing and electron-beam irradiation.
- The activation and driving forces of this rotation mode, especially under electron irradiation, are poorly understood.
Purpose of the Study:
- To elucidate the collective rotation mechanism of nanoparticles under electron irradiation.
- To understand how this rotation drives nanoparticle migration and coalescence.
- To identify the fundamental origins of the observed rotation behavior.
Main Methods:
- In situ transmission electron microscopy (TEM) to observe nanoparticle behavior.
- Molecular dynamics (MD) simulations to model atomic interactions.
- Small-strain theory to analyze mechanical behavior.
Main Results:
- A collective rotation mechanism induced by transient thermal spikes under electron irradiation was identified.
- Platinum (Pt) and AuPt nanoparticles coalesced into larger islands with coherent {111} twin structures via nonrandom lattice rotation.
- Asymmetric temperature gradients were demonstrated as the fundamental cause of the rotation behavior.
Conclusions:
- Transient thermal spikes under electron irradiation induce collective nanoparticle rotation.
- This rotation mechanism drives nanoparticle coalescence into specific twin structures.
- Asymmetric temperature gradients are the fundamental drivers of electron-beam-induced nanocrystal migration and rotation.
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