Approaches to modelling irradiation-induced processes in transmission electron microscopy

Area of Science:

• Materials Science
• Nanotechnology
• Computational Chemistry

Background:

• High-resolution transmission electron microscopy (HRTEM) enables in situ observation of dynamic processes.
• Electron irradiation can induce significant transformations in nanomaterials.
• Understanding irradiation-induced chemical reactions is crucial for materials design.

Purpose of the Study:

• To summarize experimental observations of electron irradiation effects in HRTEM.
• To detail atomistic modeling of irradiation-induced processes in nanomaterials.
• To elucidate the mechanisms behind observed nanostructure transformations.

Main Methods:

• Utilized first-principles or tight-binding molecular dynamics (MD) for single irradiation events.
• Employed classical MD simulations coupled with kinetic Monte Carlo for continuous irradiation.
• Analyzed atomistic-level details of chemical reactions and structural changes.

Main Results:

• Simulated the formation of sulfur-terminated graphene nanoribbons within carbon nanotubes via irradiation-selective reactions.
• Modeled fullerene formation during continuous electron irradiation of graphene flakes.
• Identified key mechanisms driving these nanoscale transformations.

Conclusions:

• Atomistic modeling provides critical insights into electron irradiation-induced nanomaterial evolution.
• Electron irradiation can be harnessed to synthesize specific nanostructures like fullerenes and graphene nanoribbons.
• This work advances the understanding of nanoscale chemical reactivity under electron beam exposure.