Fundamental & Computational Sciences Directorate
Pacific Northwest National Laboratory
October 9, 2015
The last few years have seen a paradigm change in (scanning) transmission electron microscopy ((S)TEM) with unprecedented improvements in spatial, spectroscopic and temporal resolution being realized by aberration correctors, monochromators and pulsed photoemission sources. Spatial resolution now extends to the sub-angstrom level, spectroscopic resolution into the sub-100meV regime and temporal resolution for single shot imaging is now on the nanosecond timescale (stroboscopic imaging extends this even further to femtoseconds). The challenge now in performing experiments in an (S)TEM is to implement the in-situ capabilities that will allow both engineering and biological systems to be studied under realistic environmental conditions. Performing experiments using in-situ stages or full environmental microscopes presents numerous challenges to the traditional means of analyzing samples in an electron microscope – we are now dealing with the variability of dynamic process rather than a more straightforward static structure. In this presentation, I will discuss the recent developments in the design and implementation of in-situ stages being pursued at the Pacific Northwest National laboratory (PNNL). Examples of the use of these capabilities for the direct imaging of interfaces and defects, to identify the fundamental processes involved in nucleation and growth of nanostructures from solution, and to investigate the electrochemical processes taking place in next generation battery systems will be presented. As the in-situ stages have been designed to be incorporated into both high spatial resolution aberration corrected (S)TEM as well as into high temporal resolution Dynamic TEM (DTEM), the potential for future experiments to study fast dynamics, including those in live biological structures, will also be discussed.