Analytical and Microstructural Microscopy Approaches for Materials Characterization

Abstract:

The atomic-level structure and chemistry of materials ultimately dictate their observed macroscopic properties and behavior. As such, an intimate understanding of these characteristics allows for better materials engineering and improvements in the resulting devices. Analytical microscopy techniques, such as transmission and scanning electron microscopy (TEM and SEM) offer high-resolution means to probe the micro- and nano-scale features of a sample, providing information about its structural, chemical, and electrical properties. A thorough comprehension of the physical origins of the signals collected during such experiments enables informed interpretation of the results and more compelling conclusions about the data.

This talk will present practical examples of electron microscopy combined with focused ion beam microscopy (FIB). The methodological foundations of these techniques will be reviewed in order to provide a basis for better understanding the results that can be obtained from such tools. Beyond the standard high resolution TEM methods (HRTEM), analytical techniques including high-angle annular dark field (HAADF) TEM and electron energy loss spectroscopy (EELS) will be described, with emphasis on how such methods can provide practical information in real material systems. Recently developed EELS data analysis methods utilizing machine learning strategies will also be demonstrated. For all of these techniques, real-world examples will be drawn from multiple fields of work, including analyses of SiC wide bandgap MOSFET devices and solid oxide fuel cell (SOFC) cathode materials.