Department of Materials Science Fall Seminar Series: Xijie Wang

Description

Xijie Wang, a distinguished scientist in Stanford's SLAC National Accelerator Laboratory, will give a talk titled "Mapping Structure Dynamics and Energy Flow in Materials Using MeV Electrons" as part of the Department of Materials Science and Engineering's Fall Seminar Series.

This is a hybrid event; email DMSE@jhu.edu for the Zoom link.

Abstract:

Most innovation in materials science and engineering resides in our ability to understand and control the intimate relationship between the structure of materials and their properties. The traditional route of discovering innovative new material properties has been to explore the structural and compositional phase space that is accessible at (or near) thermodynamic equilibrium. The characterization, manipulation and, ultimately, control of material properties far from equilibrium offers almost completely untapped possibilities for uncovering novel states/phases of materials; many without equilibrium analogs. MeV ultrafast electron scattering has become a new frontier in materials science due to its capability of following dynamics on femtoseconds scale with the high spatial resolution and sensitivity [1-3]. Furthermore, MeV electrons experience less multiple-scattering, and possess "real" flat Ewald-sphere; MeV ultrafast electron diffraction (MeV-UED) is an ideal tool to explore material structure and dynamics using total scattering technique. MeV-UED had broad and transformative impact on ultrafast science, such as the first 2-D materials ultrafast structure dynamics [4], light-induced transient states of quantum materials [5-6], the first direct imaging of fundamental chemical processes [7-9] and hydrogen bond dynamics in liquid water. After briefly review MeV ultrafast electron scattering, I will highlight couple materials science and engineering examples enabled by MeV-UED, such as the first operando experiment in ultrafast [10], mapping energy and charge flow in nano-scale heterostructures[11-12] and ultrafast visualization of incipient plasticity in dynamically compressed matter [13].