Phase imaging methods in the scanning transmission electron microscope

Abstract

Scanning transmission electron microscopy (STEM) has become an essential tool for investigating materials, providing detailed characterization at nano and atomic scales. By combining subangstrom resolution Z-contrast imaging with analytical X-ray and electron spectroscopies, STEM allows the visualization of atomic arrangements, crystal defects, and interfaces, understanding sample properties and correlating these with the functionalities of materials and devices. Recent advancements in phase imaging techniques, including differential phase contrast (DPC) and electron ptychography, have further enhanced STEM capabilities. These methods allow direct imaging of electromagnetic fields, the study of beam-sensitive materials with high dose efficiency, or resolving the 3D structure of materials, proving invaluable for investigating intricate nanoscale phenomena. This review introduces phase imaging methods in the STEM and explores how the most recent innovations are driving progress in nanoscience, deepening material insights and shaping next-generation applications in electronics, energy storage, and catalysis.