Nonlocality in spherical-aberration-corrected HAADF STEM images

Nonlocality in spherical-aberration-corrected high-angle annular dark-field (HAADF) scanning transmission electron microscope (STEM) images is theoretically and experimentally examined using the absorption potential describing thermal diffuse scattering (TDS). A detailed comparison between the simulated and the experimentally obtained high-quality HAADF STEM images of an Si(110) bulk structure and a PbTiO₃(100)/SrTiO₃(100) interfacial structure unambiguously demonstrates the need to use a nonlocal TDS absorption potential. The nonlocality in the TDS absorption potential cannot be ignored in a detailed analysis of spherical-aberration-corrected HAADF STEM images of materials consisting of several heavy elements, although it can be completely disregarded for those consisting of only light elements.