College of Engineering

Designing Functional Materials One Atom at a Time

Abstract:
Defects in materials are inevitable. Sir Colin Humphreys wrote “crystals are like people, it is the defects in them which tend to make them interesting”.¹ Advances in supercomputing capabilities and first-principles calculations based on density-functional theory now make it possible to successfully describe the properties of “real” materials with disorder, defects, and imperfections starting from the atomic scale. Concurrent advances in scanning transmission electron microscopy enable imaging and spectroscopy of the atomic and electronic structure of materials with unprecedent spatial and energy resolution. Naturally then, the combination of theory and microscopy provides an unparalleled probe to unravel the structure-property correlations in real materials. In this presentation, I will discuss my group’s efforts to develop new materials with defects and disorder for energy and optical applications. Examples will include design of defective oxides for cleaner combustion of hydrocarbons,² two-dimensional high-entropy alloys for CO₂ reduction,^3,4 and chalcogenide perovskites with colossal optical anisotropy.⁵

Bio:
Rohan Mishra is an Associate Professor of Mechanical Engineering & Materials Science, and Physics (by courtesy) at Washington University in St. Louis. He is also an affiliate faculty at the Institute of Materials Science & Engineering at Washington University, where he serves as the Director of Graduate Studies. From 2012-2015, he was a postdoctoral researcher in the Scanning Transmission Electron Microscopy group at Oak Ridge National Laboratory with a joint-affiliation from the Department of Physics at Vanderbilt University. He has a Bachelor in Technology in Metallurgical and Materials Engineering from National Institute of Technology Karnataka in India (2008) and a PhD in Materials Science and Engineering from The Ohio State University (2012). He leads the Materials Modeling and Microscopy group (mcube.wustl.edu) that works on establishing quantitative structure-property correlations in materials using a synergistic combination of electronic structure theory and electron microscopy. Their end goal is the rational design of materials with properties tailored for various energy applications. Mishra has coauthored over 80 journal articles.

1.     C. J. Humphreys, in Introduction to Analytical Electron Microscopy,  (Eds: J. J. Hren, J. I. Goldstein, D. C. Joy), Springer US, Boston, MA 1979, 305.
2.     G. F. Luo et al., J. Phys. Chem. C 123, 17644 (2019).
3.     J. Cavin et al., Adv. Mater. 33, 2100347 (2021).
4.     Z. Hemmat et al., Adv. Mater. 32, 1907041 (2020).
5.     H. Mei et al., arXiv:2303.00041 (2023).