Development and Application of Electron Tomography at Atomic Resolution

摘要

In this article, we introduce an atomic resolution tomography method using electron holography reconstructed from Cs corrected electron microscope. This method is allowed for quantitative analysis of three-dimensional atomic structure and surface topography from only one projected direction. Recently, TEM has capability to analyze material with sub-A resolution with a Cs corrector. However, the real structure in three dimensions (3D) and the whole shape of material still can not be directly revealed from electron micrographs due to the limitation of two dimensional projected image. Certainly, materials properties can be corrected with the atomic arrangement in three dimensions. The ultimate goal of electron microscopy is to act as a communication channel between structure and properties of materials. It is therefore a very important issue how to determine the atomic positions in three dimensions from two dimensional projected images. We demonstrated our methodology using the simulated exit wave functions of a bilayer graphene, oleic acid molecules and experimental cases including of Ge nano-crystal, MgO and nano Au bridge.