Differential Phase Contrast Scanning Transmission Electron Microscopy at Atomic Resolution

Abstract

Understanding the atomic-scale structures of surfaces and interfaces is essential to control the functional properties of many materials and devices. Recent advances in aberration-corrected scanning transmission electron microscopy (STEM) have made possible to directly characterize localized structures in materials, especially at interfaces, in both atomic structures and chemistry. In STEM, a finely focused electron probe is scanned across the specimen and the transmitted and/or scattered electrons from a localized volume of the material are detected by the post-specimen detector(s). By controlling the detector geometry, we gain flexibility in determining the contrast characteristics of the STEM images and the formation mechanisms involved.