3D electron diffraction techniques

Abstract

3D electron diffraction is an emerging technique for the structural analysis of nanocrystals. The challenges that 3D electron diffraction has to face for providing reliable data for structure solution and the different ways of overcoming these challenges are described. The route from zone axis patterns towards 3D electron diffraction techniques such as precession-assisted electron diffraction tomography, rotation electron diffraction and continuous rotation is also discussed. Finally, the advantages of the new hybrid detectors with high sensitivity and fast readout are demonstrated with a proof of concept experiment of continuous rotation electron diffraction on a natrolite nanocrystal.

Nanocrystals of Lead Chalcohalides: A Series of Kinetically Trapped Metastable Nanostructures

“…An extremely mild illumination was adopted to avoid any alteration or amorphization of the sample and to slow down the accumulation of organic contaminants. 3D-ED data were recorded with an ASI Timepix detector, 27 which is able to register the arrival of single electrons and deliver a pattern that is virtually background-free. The camera length was 180 mm, with a theoretical resolution limit of 0.75 Å.…”

Electron Diffraction on Flash-Frozen Cowlesite Reveals the Structure of the First Two-Dimensional Natural Zeolite

“…The fast transformation imposed by the TEM vacuum prevented us from studying the native cowlesite structure by 3D ED, even after sample cooling and after adopting ultrafast acquisition protocols that minimize beam-induced amorphization. 35 , 40 …”

Hydrogen disorder in kaatialaite Fe[AsO2(OH)2]5H2O from Jáchymov, Czech Republic: determination from low-temperature 3D electron diffraction

“…Although the kinematical approximation does not lead to the same accuracy in terms of structural parameters, it is enough to gain an insight into the hydrogen positions and reveal the existence of hydrogen disorder in the natural kaatialaite (Table S1). In general, whatever 3D ED technique is used (Gemmi & Lanza, 2019), it represents an interesting point for structures of many natural minerals, especially the minerals coming from second mineralization processes that are not well crystallized and present rather low symmetry. Their structure cannot be refined considering the dynamical theory because of computational burden and their imperfect crystallinity (Shi et al, 2013;Gemmi et al, 2015;Nannenga et al, 2014;Cichocka et al, 2018).…”