F.MT03: Frontiers of Imaging and Spectroscopy in Electron Microscopy

Joseph Patterson, University of California, Irvine

Live Keynote II: Frontiers of Imaging and Spectroscopy in Electron Microscopy

Written by Emma Perry

Joseph Patterson outlines how his group, and many others, focus on performing very thorough analysis using one technique, publishing, and then considering if another technique could be interesting. After describing some very interesting studies that have been conducted this way, the concept of a distributed experimental methodology is introduced.

Liquid and cyro TEM each have their advantages such that they are well suited to studying different types of mechanisms. In cyro TEM you get a snap shot. In liquid TEM you see the dynamics evolve. In cyro TEM it can be very difficult to infer a complex mechanism but this can be overcome by taking a large number of snapshots. In liquid TEM the beam interactions can affect the dynamics of the system but this can be overcome by switching sample location part way through the evolution. All of the time you are limited by how many experiments you can physically do and by the dose that you can apply to your samples.

The alternative approach is to take a holistic overview. For example you can use liquid TEM to understand the timescales of the mechanism with a low frame rate to limit the dose. Then maybe one stage of the mechanism is more complicated so you could focus on this by collecting cyro TEM at the appropriate time. Then maybe you have some questions on a specific part so you can collect cyro STEM or 3D TEM. It is possible to build a reliable model by using the advantages of each technique to support the weakness of others.