| Abstract Scope |
Four-dimensional scanning transmission electron microscopy (4D-STEM) has rapidly become a powerful platform for quantitative materials characterization at atomic resolution. Yet the growing range of reconstruction methods can make the technique difficult to navigate for new practitioners. This tutorial-style presentation introduces a unified perspective on modern diffractive imaging approaches, highlighting their common physical foundations, practical trade-offs, and guidance for selecting appropriate methods for different characterization problems. Building on this framework, I will discuss recent advances that extend these concepts beyond conventional STEM, including nanobeam and pencil-beam ptychography, as well as accurate low-energy electron scattering models and reciprocal multislice simulations for electron backscatter diffraction (EBSD) in non-periodic materials containing defects, strain, and disorder. Together, these developments lay the groundwork for 4D-STEM-in-SEM: bringing atomic-resolution diffractive imaging to low accelerating voltages in more accessible scanning electron microscopes, enabling quantitative characterization of bulk materials beyond the traditional transmission electron microscope. |