Locating light and heavy atomic column positions with picometer precision using ISTEM

- A statistical method is used to measure atomic column positions.
- Light and heavy columns are located with picometer precision using ISTEM images.
- A quantitative comparison is made between ISTEM and HAADF STEM imaging.

Recently, imaging scanning transmission electron microscopy (ISTEM) has been proposed as a promising new technique combining the advantages of conventional TEM (CTEM) and STEM (Rosenauer et al., 2014 [1]). The ability to visualize light and heavy elements together makes it a particularly interesting new, spatially incoherent imaging mode. Here, we evaluate this technique in term of precision with which atomic column locations can be measured. By using statistical parameter estimation theory, we will show that these locations can be accurately measured with a precision in the picometer range. Furthermore, a quantitative comparison is made with HAADF STEM imaging to investigate the advantages of ISTEM.