Atomic-Scale Structure Dynamics of Nanocrystals Revealed by In-Situ and Environmental Transmission Electron Microscopy.

Nanocrystals are of great importance in material sciences and industry. Engineering nanocrystals with desired structures and properties is no doubt one of the most important challenges in the field, which requires deep insight into atomic-scale dynamics of nanocrystals during the process. The rapid developments of in-situ transmission electron microscopy (TEM), especially environmental TEM have revealed insights into nanocrystals to digest. According to the considerable progress based on in-situ electron microscopy, we will give a comprehensive review on nanocrystal dynamics from three aspects: nucleation and growth, structure evolution, and dynamics in reaction conditions. In the nucleation and growth part, we organize existing nucleation theories and growth pathways based on liquid and gas-solid phases. In the structure evolution part, we focus on in-depth mechanistic understanding of the evolution, including defects, phase, and disorder/order transitions. In the part of dynamics in reaction conditions, we discuss solid-solid and gas-solid interfaces of nanocrystals in atmosphere and correlate the structure-property relationship. Even though impressive progress has been made, additional efforts are required to develop the integrated and operando TEM methodologies for unveiling nanocrystal dynamics with high spatial, energy, and temporal resolutions. This article is protected by copyright. All rights reserved.