Binbin Luo, Qian Chen, and their colleagues at the University of Illinois Urbana–Champaign and Northwestern University used the Hummingbird Scientific in situ TEM liquid flow sample holder to investigate the nucleation and crystal growth of gold nanoparticles with different shapes. By combining in situ liquid-cell transmission electron microscopy (LC-TEM) with molecular dynamics simulations, the team directly visualized both smooth layer-by-layer growth and rougher multilayer out-of-plane growth under realistic liquid conditions.

By tuning nanoparticle shape and solution conditions, the researchers demonstrated that these growth modes can be independently controlled, leading to the discovery of two previously unobserved crystallization pathways—mounds with straight steps and layer-by-layer growth with rough steps. These behaviors are governed by nanoparticle diffusion rates and the balance between in-plane and step-edge diffusion barriers. Experimentally measured parameters, combined with kinetic Monte Carlo simulations, enabled the construction of a master phase diagram that unifies crystal growth and surface morphology across four orders of magnitude in particle size, offering new strategies to control surface structure and defect density in nanomaterials.

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These insights were made possible by the Hummingbird Scientific in situ TEM liquid flow sample holder, which provides a stable, continuously flowing liquid environment and the resolution required to track individual nanoparticles during crystallization in real time. This capability allows researchers to directly connect single-particle dynamics to emergent crystal growth behavior—unlocking new opportunities for studying and engineering nanoscale materials in liquid environments.

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Reference:

Binbin Luo, Ziwei Wang, Tine Curk, Garrett Watson, Chang Liu, Ahyoung Kim, Zihao Ou, Erik Luijten, Qian Chen, Nature Nanotechnology 18 589-595 (2023) DOI: 10.1038/s41565-023-01355-w