Team I: Multi-Dimensional Electron Microscopy at Atomic Resolution

Motivation

Understanding 3D structure and evolution of matter at the atomic scale is central to modern science and technology. This problem has been solved for crystalline, static materials. The remaining challenges are threefold: to determine the 3D structure of non-crystalline matter, to do so as a function of time, and finally to understand the relationship between this evolution and the stimuli that drive it. To tackle these major challenges, STROBE will advance and integrate different electron microscopyThe definition of the term will appear here.../diffraction techniques through common underpinning technologies: advanced algorithms, fast detectors and big data handling.

Our Approaches

 I.1) Capturing the 3D coordinates of individual atoms in non-crystalline materials. In combination of state-of-the-art electron microscopes and powerful 3D reconstruction algorithms, we will apply atomic electron tomography (AET) to localize and identify all atomic species in complex systems (including dopants, interstitials, light elements, and vacancies) with high precision. An ultimate goal is to understand the 3D interaction of point defects, dislocations, and grain boundaries at atomic resolution and to correlate it with material properties and functionality. 

 II.2) Multimodal, correlative EM for atomic-resolution imaging of liquid and solid-state systems. By integrating multimodal EM with advanced algorithms, we aim to achieve atomic resolution imaging of nucleation events with precise measurements of sample and environmental conditions. We will also combine high-speed direct detectors with in situ TEM and ultrafast electron diffraction to probe energy materials and the electrical double layer in liquid and solid-state systems. Using liquid cells developed for STEM, we will map the local ionic density with Z-contrast imaging, as a function of applied potential, distance from the electrode, bulk salt concentration, pH, ion type and valence. Finally, we will develop ultrafast electron diffraction with high spatio-temporal resolution and use it to probe the dynamics of complex materials.

  II.3) Unraveling the 3D structure of biological complexes at  atomic resolution. Single-particle cryo-EM has become a very important method for 3D structure determination of macromolecules at near-atomic resolution. STROBE will integrate fast direct electron detectors, state-of-the-art cryo-EM, novel image reconstruction algorithms and big data expertise to allow routine determination of the 3D structure of biological complexes at atomic resolution. We will also use electron diffraction to determine the 3D atomic structure of protein nanocrystals in real time.