Detection of Single Atoms and Buried Defects in Three Dimensions by Aberration-corrected Electron Microscope with 0.5 ? Information Limit

Abstract

The ability of electron microscopes to analyze all the atoms in individual nanostructures is limited by lens aberrations. However, recent advances in aberration-correcting electron optics have led to greatly enhanced instrument performance and new techniques of electron microscopy. The development of an ultrastable electron microscope with aberration-correcting optics and a monochromated high-brightness source has significantly improved instrument resolution and contrast. In the present work, we report information transfer beyond 50 pm and show images of single gold atoms with a signal-to-noise ratio as large as 10. The instrument's new capabilities were exploited to detect a buried Σ3 {112} grain boundary and observe the dynamic arrangements of single atoms and atom pairs with sub-�ngstrom resolution. These results mark an important step toward meeting the challenge of determining the 3D atomic-scale structure of nanomaterials.