Grain boundaries are interfaces or boundaries that separate neighboring grains or crystals within a material. These boundaries play a crucial role in determining the mechanical, electrical, and thermal properties of materials. Grain boundaries can influence the strength, ductility, and corrosion resistance of materials, as well as their behavior in response to external stresses. Researchers studying grain boundaries seek to understand the structure, composition, and properties of these boundaries in order to manipulate and control them to improve the performance of materials. This research area involves techniques such as electron microscopy, diffraction, and computational modeling to investigate grain boundaries at the atomic scale. Overall, the study of grain boundaries is important for the development of advanced materials with tailored properties for various applications in engineering, electronics, and other fields.