In Situ Liquid Cell Electron Microscopy Atomic Level Heterogeneity and Fluctuations at Solid-Liquid Interfaces

The goal of this program is to develop and advance a state-of-art in situ liquid cell transmission electron microscopy (TEM) platform to elucidate how atomic level heterogeneity and fluctuations at solid-liquid interfaces determine the physical and chemical processes of materials, with a primary focus on nucleation and nanoscale materials transformations. The development of advanced instrumentation for imaging and chemical identification through liquids with atomic resolution provides transformative opportunities for the investigation of non-conventional nucleation and nanoscale materials transformations involving non-equilibrium processes. The atomic-scale imaging of nucleation and resolving nonequilibrium nanoscale material transformations in liquids has been a significant challenge due to the difficulties in maintaining sufficient resolution and contrast in thick liquid samples while also limiting electron beam damage.

This program develops high-resolution liquid cells, advances fast and low dose high-resolution imaging with high quantum efficiency but avoiding electron beam damage, and image analysis with machine learning. It uses a state-of-art high-resolution liquid cell TEM platform to study short-range ordering and prenucleation clusters in liquids, nucleation and structural evolution of model 2D materials, hydrogen induced phase transformation in Pd nanocrystals, and solid-liquid (electrode-electrolyte) interfaces. The program contributes to an understanding of the mechanisms of observed transformations with an integrated experimental and theoretical approach and helps to address critical scientific problems centered on non-conventional nucleation and non-equilibrium material transformations.