MSE Seminar Series: Electron Microscopy: Redefining the Limits of Observation
Juan Carlos Idrobo, Associate Professor of Materials Science & Engineering, University of Washington
The field of electron microscopy (EM) has undergone significant progress in the past two decades, owing to advances in hardware and software technologies. Recent developments in electron microscopy, including the emergence of aberration-corrected imaging [1,2], monochromated spectroscopy [3,4], direct electron cameras , and stable cryogenic stages and biasing holders , has enabled researchers to visualize mater as never before.
While electron microscopy has made significant strides in many domains, there remain areas it has yet to fully explore. Specifically, topology and chirality stand out. These intrinsic material properties, originating at the quantum level, play pivotal roles in influencing macroscopic attributes such as Hall transport and optical absorption.
We also have grown familiar with the capability of electron microscopy to clearly discern individual atoms and investigate their local bonding using electron energy-loss spectroscopy (EELS) techniques. Yet, the detection of isotopic species and understanding their impact on atomic configurations or the thermal properties of materials had remained beyond the reach of the technique.
In this presentation, I will start with a succinct overview of the evolution of electron microscopy. Subsequently, we will delve into the intricacies of studying Hall transport properties with sub-nanometer precision, the detection of chiral phonons at the nanoscale, and the prerequisites for achieving two-dimensional isotopic mapping with sub-nanometer accuracy. Throughout the talk, I will showcase experimental findings on these subjects and explore how their detection is ushering in a new era in materials characterization.
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 O. L. Krivanek., N. Dellby, A.J. Spence, R.A. Camps, & M.L. Brown, In Proceedings of EMAG 1997, Cambridge, UK, (ed. Rodenburg, J.M.) 35–39 (Institute of Physics, Bristol UK, 1997).
 O.L. Krivanek, et al., Nature 514 (2014) p. 209–212 (2014).
 T. Miyata et al., Microscopy 63 (2014), p377–382.
 J.L. Hart et al., Sci. Reports 7 (2017), p. 8243.
 I. El Baggari, et al., PNAS 115 (2018), p. 1445-1450.
Juan Carlos Idrobo is an Associate Professor in the Materials Science & Engineering Department at the University of Washington. His research involves developing and applying analytical techniques in electron spectroscopy within aberration-corrected scanning transmission electron microscopy to study material properties at the atomic scale. He has published over 180 papers in peer-reviewed journals, accumulating more than 22,000 citations. In 2018, Idrobo was recognized by Clarivate Analytics as one of the top 1% of researchers cited in Cross-Field in Web of Science, spanning from 2006 to 2016. Idrobo holds degrees in Physics from Universidad de Los Andes in Colombia (B.Sc., 2000), the University of Illinois at Chicago (Master, 2003), and the University of California, Davis (Ph.D., 2004). He was honored as a Fellow of the Microscopy Society of America in 2023.