Joerg Jinschek1

1, The Ohio State University, Columbus, Ohio, United States

At any stage in research and development of (new) functional nanomaterials, studies of these nanomaterials’ structure, properties, and function are critical, including detailed atomic-scale insights. To our advantage, in-situ electron microscopy (EM) enables visualization of structural evolution and thereby has become a powerful tool for characterizing actual state and function of those nanostructures under (near) operational conditions [1,2].
Applying atomic-scale EM techniques in in situ studies is, however, still extremely demanding. A key challenge is to establish in situ conditions in the close vicinity of the specimen while maintaining the microscope’s overall performance and stability. Ongoing activities also concentrate on methodological aspects of atom sensitive imaging while controlling electron beam / structure interactions [3,4]. Recent advances in in-situ atomic-scale EM will be highlighted.
Optimized in situ stages - based on MEMS technology – enable more accurate realization of experimental in situ conditions, and the opportunity to detect the material’s function simultaneously as well (= operando). Sample preparation in conjunction with MEMS cartridges as sample supports have been adopted [5]. Fine temperature control enables quantitative studies at elevated temperatures [6]. Others have utilized EM methods to measure the actual temperature (gradient) of the specimen more precisely [7]. Moreover, the integration of a heater into a gas-flow MEMS nanoreactor enables operando EM combining structural characterization of e.g. catalytic materials with simultaneous measurement of its activity for gaseous reactions [8].
These advancements open up for unprecedented experiments of dynamic phenomena in materials science to understand the structure-property-function relationship on the (sub)nanometer length scale.

[1] J. R. Jinschek, Chemical Communications 50 (2014) 2696.
[2] J. R. Jinschek, Current Opinion in Solid State & Materials Science 21 (2017) 77.
[3] J. R. Jinschek et al., Micron 43 (2012) 1156.
[4] S. Helveg, et al., Micron 68 (2015) 176.
[5] S. Vijayan, et al., Microscopy and Microanalysis 23 (2017) 708.
[6] L. Mele, et al., Microscopy Research and Technique 79 (2016) 239.
[7] F. Niekiel, et al. Ultramicroscopy 176 (2017) 161.
[8] S. B. Vendelbo, et al., Nature Materials 13 (2014) 884.