In Situ Three-Dimensional Electron Diffraction for Probing Structural Transformations of Single Nanocrystals

Abstract

Phase transitions of materials are usually accompanied by a remarkable change of properties. Tracing and identifying the structural changes at the atomic scale is the key to understanding the fundamental mechanisms behind their performances. However, the direct observation of three-dimensional structural transformations in single nanocrystals has been rarely achieved. Herein we reported the development of an in situ threedimensional electron diffraction (3D ED) approach for single nanocrystal structural analysis by combining 3D ED with in situ transmission electron microscopy. Each data set covering a crystal tilting range of 50°was collected in around 1 min at the set temperature using an in situ heating holder. The feasibility of this protocol was proved by its successful application in investigating the metal−insulator transition (MIT) of vanadium dioxide (VO 2 ) crystals with atomic precision. Moreover, local domains were found in the monoclinic phase before and after the annealing process, of which the orientations obey a 4-fold rotation symmetry along the a-axis.

The master key: structural science in unlocking functional materials advancements

“…crystallography and offers unique insights into the dynamic behavior and structural transformations of materials at the atomic and nanoscale levels. One of the primary ways in which in situ 3DED contributes to the development of new functional materials is by offering a dynamic view of phase transitions and crystal growth (Batuk et al, 2023;Broadhurst et al, 2020;Karakulina et al, 2018;Wu et al, 2022). In the same vein, precession electron diffraction tomography (PEDT) combines the principles of electron diffraction and tomography (Day et al, 2022;Boullay et al, 2013).…”

High Temperature Electron Diffraction on Organic Crystals: In Situ Crystal Structure Determination of Pigment Orange 34

“…Even inorganic materials are rarely investigated by ED at higher temperatures. One recent example is the investigation of the metal–insulator transition of VO 2 crystals, studied at temperatures above 200 °C . To our knowledge, no profound temperature-dependent structural investigation above room temperature has been carried out on molecular crystals with electron diffraction so far.…”

“…One recent example is the investigation of the metal−insulator transition of VO 2 crystals, studied at temperatures above 200 °C. 30 To our knowledge, no profound temperature-dependent structural investigation above room temperature has been carried out on molecular crystals with electron diffraction so far. Here, we report on the crystal structure determination of the organic compound Pigment Orange 34 (C 34 H 28 Cl 2 N 8 O 2 ) between −180 and +220 °C by high-end 3D ED methods.…”

Designable Synthesis of Layered Silicates and Tunable Interlayer Expanded to Zeolites

“…3D electron diffraction (3D ED) technique has been developed and improved to carry out structure characterization in past decades [24][25][26] It has made extensive contributions to structural solution of porous materials, metal oxides, etc. [27][28][29][30][31] By rotating the crystalline specimen and collecting the electron diffraction patterns at different angles, 3D ED models in reciprocal space would be reconstructed, with which the crystallographic information such as unit cell parameters, reflection intensities, and extinction conditions could be obtained and analyzed. As a result, atomic-level crystal structure solutions can be obtained using direct methods, charge flipping, etc.…”