Connecting energetics to dynamics in particle growth by oriented attachment using real-time observations

Area of Science:

• Materials Science
• Crystallography
• Nanotechnology

Background:

• Crystallization by oriented attachment (OA) is crucial for nanomaterial synthesis.
• Quantitative understanding of OA, influenced by crystal structure, solvent, interparticle forces, and particle dynamics, is lacking.

Purpose of the Study:

• To quantitatively link experimentally derived interparticle potentials to underlying interactions in OA.
• To elucidate the mechanisms governing particle assembly during OA using ZnO as a model system.

Main Methods:

• In situ transmission electron microscopy (TEM) observations of single particle and ensemble assembly dynamics.
• Simulations of interparticle forces and responses.
• Analysis of interparticle potentials and interactions.

Main Results:

• OA is driven by electrostatic ion-solvent correlations and dipolar interactions at separations beyond 5 nm.
• Particle coalignment precedes strong attractions, with a negligible attachment barrier.
• Dissipative factors in TEM fluid cells cause abnormal diffusivities, favoring rotation over translation.

Conclusions:

• The study provides a quantitative understanding of OA mechanisms.
• Electrostatic and dipolar forces, along with anisotropic diffusion, are key drivers of OA.
• This work advances the control and design of nanomaterial synthesis via OA.