Electron crystallography and electron diffraction instrumentation
What is it about?
With scientists in mind who don’t yet have an in-depth knowledge of 3D electron diffraction (3D ED) but a general understanding of X-ray diffraction methods, this article aims to provide an overview of the most important techniques, achievements, advantages, and challenges in the field, supported by several case studies of data collected on Eldico’s ED-1.
Why is it important?
As the analysis of crystal structures of new materials is as important as ever, there is the need from industry and academia to determine crystal structures of smaller crystal sizes than previously possible. With experiments generally conducted on transmission electron microscopes, electron diffraction (ED) brings forth the ability to measure crystals in the range of tens to hundreds of nanometers in both direct (imaging mode) and reciprocal space (diffraction mode). The development of novel electron diffraction techniques therefore is a good complement to established X-ray diffraction (XRD) methods in cases where crystals larger than 1 μm cannot be obtained. The boundaries of what is possible to measure are being expanded as ED allows for the refinement of single-crystal structures that had been previously too complex or too small for X-ray diffraction methods. Besides a comparison between X-ray diffraction and electron diffraction, special emphasis is given to dedicated 3D ED instrumentation and their requirements, as well as presenting benchmark experiments using such electron diffractometers.