MSE Colloquium: Mitra Taheri, Understanding Local Versus Global Behavior in Grain and Domain Boundary Network Evolution using Quantitative In Situ Microscopy Techniques
Evolution of grain boundary and related domain networks is of significant importance in dictating material properties. While much attention has been given to recrystallization and other phenomena, the development of twin boundaries and related domain networks is still in question. Understanding these networks, and the interaction of twins and related domains with one and two-dimensional defects is critical. This talk focuses on methodologies for using quantitative in situ microscopy tools to understand grain boundary- defect and defect-domain interactions in various materials, including metals and ferroelectric ceramics. Results will be shown for both mesoscale and nanoscale interactions, and will highlight the difference between global and local behavior with respect to defect-interface relationships in materials with multiple interfaces or boundaries. A general discussion of current and future electron microscopy techniques for probing defect evolution will also be presented.
Mitra Taheri is the Hoeganaes Associate Professor in the Department of Materials Science & Engineering at Drexel University. At Drexel, she runs the “Dynamic Characterization Group,” which focuses primarily on the use of cutting edge in situ microscopy to develop and characterize various materials. While at Drexel, she has been the recipient of both the NSF and DOE Early Career awards, an ONR Summer Faculty Fellowship, and has been a visiting scholar at the Politecnico di Milano, in Milan, Italy. Taheri received her PhD in Materials Science & Engineering (MSE) from Carnegie Mellon University, As a PhD student, she received a US Steel Graduate Scholarship, a Materials Research Society Graduate Student Award, a full member to Sigma Xi, and was a visiting scholar at RWTH Aachen University in Germany, the National Center for Electron Microscopy (LBL), and the Northwestern University’s Center for Atom Probe Tomography. Following her doctoral studies, Taheri was an NRC Postdoctoral Fellow at the Naval Research Laboratory (NRL) and a Director’s Postdoctoral Fellow at Lawrence Livermore National Laboratory (LLNL), where she and her group at LLNL won an R&D 100 award, a Nano-50, and the Microscopy Society of America’s Microscopy Innovation Award.