Transmission Electron Microscopy of Shape-Controlled Nanocrystals and Their Assemblies

TLDR

Nanophase materials’ properties depend on crystal and surface structures, and TEM provides atomic‑resolution real‑space imaging that uniquely characterizes these structures. The article introduces TEM fundamentals and their use for determining the structure of shape‑controlled nanocrystals and assemblies. TEM employs a nanometer‑scale electron probe and electron‑energy‑loss spectroscopy to identify and quantify chemical, electronic, valence, and thermodynamic, electric, and mechanical properties of individual nanocrystals, enabling structure–property mapping. The study demonstrates that electron‑energy‑loss spectroscopy and in‑situ TEM can map valence states and measure thermodynamic, electric, and mechanical properties, linking structure to property in individual nanostructures.

Abstract

The physical and chemical properties of nanophase materials rely on their crystal and surface structures. Transmission electron microscopy (TEM) is a powerful and unique technique for structure characterization. The most important application of TEM is the atomic-resolution real-space imaging of nanoparticles. This article introduces the fundamentals of TEM and its applications in structural determination of shape-controlled nanocrystals and their assemblies. By forming a nanometer size electron probe, TEM is unique in identifying and quantifying the chemical and electronic structure of individual nanocrystals. Electron energy-loss spectroscopy analysis of the solid-state effects and mapping the valence states are even more attractive. In situ TEM is demonstrated for characterizing and measuring the thermodynamic, electric, and mechanical properties of individual nanostructures, from which the structure−property relationship can be registered with a specific nanoparticle/structure.