This session is part of the "Beyond the Scope: CEMAS Discussion Series."

Four-dimensional scanning transmission electron microscopy (4D-STEM), which utilizes the recent advances of fast pixelated STEM detectors, has opened new tremendous possibilities in characterization of materials, acquiring new information by accessing extra spatial dimensions of the detector space. This presentation intends to provide a broad overview of the history and technical aspects of 4D-STEM, the advantages and limitations of current generation fast STEM detectors, as well as many characterization techniques enabled by 4D-STEM, including electron ptychography with extreme spatial resolution, differential phase-contrast imaging of electromagnetic fields within materials, electron channeling contrast imaging of atomic structure and defects, and diffraction contrast imaging and fluctuation microscopy of local structural heterogeneity.