Structure analysis of materials at the order–disorder borderline using three-dimensional electron diffraction

Abstract

Diffuse scattering, observed as intensity distribution between the Bragg peaks, is associated with deviations from the average crystal structure, generally referred to as disorder. In many cases crystal defects are seen as unwanted perturbations of the periodic structure and therefore they are often ignored. Yet, when it comes to the structure analysis of nano-volumes, what electron crystallography is designed for, the significance of defects increases. Twinning and polytypic sequences are other perturbations from ideal crystal structure that are also commonly observed in nanocrystals. Here we present an overview of defect types and review some of the most prominent studies published on the analysis of defective nanocrystalline structures by means of three-dimensional electron diffraction.

Cs3Cu4In2Cl13 Nanocrystals: A Perovskite-Related Structure with Inorganic Clusters at A Sites

“…Therefore, this mechanism acts at a scale of a few cell repetitions, and even a single NC is better addressed as a crystalline assembly with a dominant coherent volume neighbored by more disordered areas. This is not an unusual situation for nanocrystalline materials, as shown by a number of recent works employing the 3D ED technique. − …”

“…This is not an unusual situation for nanocrystalline materials, as shown by a number of recent works employing the 3D ED technique. [35][36][37][38] Larger pseudo-triangular and pseudo-hexagonal platelet particles exhibit the same primitive cubic cell. In addition, extra reflections appeared parallel to one of the <111>* directions, which correspond to one of the main diagonal of the cubic cell ( Figure S7).…”

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

“…This relatively high value incorporates the effect of the stacking disorder and is comparable with the ones observed for other structures affected by order–disorder polytypism. 37 , 57 The so-determined structure consists of a continuous 3D zeolite framework with no dangling bonds. However, such a framework can also be described by the union of two 2D zeolitic layers weakly connected by four pairs of Si–O–Si bridges per unit cell.…”

Solid state chemistry for developing better metal-ion batteries

“…The advantage of EDT relies in the use of a weak electron beam thus reducing electron dose and minimizing electrolyte decomposition. Further advances are rooted in the full dynamical structure refinement that significantly improves the quality of crystallographic data reaching ~0.02 Å precision in atomic positions 67 and in treatment of diffuse electron scattering that provides information on planar defects and disorder 68 .…”