Atomic-Resolution STEM with Segmented Annular All-Field Detector

Abstract

In scanning transmission electron microscopy (STEM), a finely focused electron probe is scanned across the specimen and the transmitted and/or scattered electrons from a localized material volume are detected by the post specimen detector(s) as a function of raster position. By controlling the detector geometry, STEM image formation mechanisms and contrast characteristics can be, in principle, controlled. Recently, we have developed a new area detector which we refer to as the “Segmented Annular All Field (SAAF)” detector and which is capable of atomic-resolution STEM imaging. Here we will show the capability of this detector and discuss the possibility of new atomic-resolution STEM imaging mode using this SAAF detector.