Marek Malac, Misa Hayashida, and Mike Fleischauer
Fall 2018 has seen two Alberta section activities: Dr. Ray Egerton’s talk on Oct 10th 2018, and a workshop on environmental electron microscopy on Oct 25th 2018.
"Is it possible to defeat radiation damage in the TEM?"
Dr. Egerton discussed the perpetual challenge of electron microscopy: the limitations set by the radiation damage caused by the very same electron beam as used for imaging the samples. While radiation damage sets the f undamental limit on the information that can be obtained, there is plenty that can be done to optimize the data collection schemes and experiment optimization. Dr. Egerton’s presentation provided not only insights into the basic physics phenomena underlyin g radiation damage, but also practical tricks and advice on how some of these limitations can be overcome or mitigated. The results explained in his presentation are partly summarized in his recent paper in Micron [1]. For example, optimizing the incident electron energy and sample thickness can improve the resolution by perhaps a factor of 2. Furthermore, cooling the sample can help to collect data before significant diffusion has taken place.
The environmental workshop was hosted by Norcada, Hitachi High Technologies Canada, and the National Research Council–Nanotechnology Research Centre. Invited talks from Dr. Jane Howe (now of University of Toronto), Dr. Jon Veinot (University of Alberta), and Dr. Viola Birss (University of Calgary) described the evolu tion of lunar soil samples during in-situ TEM and the challenges associated with characterization of silicon and carbon structures with a few nanometer lateral dimensions, respectively. Norcada and Hitachi High Technologies Canada presented the results of their joint development of devices for in-situ electron microscopy, in particular heating MEMS chips. Their presentation was followed by hands-on demonstrations of the actual devices.
[1] R.F. Egerton, Radiation damage to organic and inorganic specimens in the TEM , Micron, 119 (2019), p.72.
Dr. Egerton presenting the limits of beam induced damage of samples in electron microscopy.
Dr. Jane Howe’s presentation at the environmental TEM workshop.
