Direct Visualization of Localized Vibrations at Complex Grain Boundaries (Adv. Mater. 13/2023)

SrTiO3 Grain Boundaries Using an electron microscope with ultrahigh‐energy‐resolution enables direct imaging of local structure, nonstoichiometry, and chemical bonding, leading to a redistribution of vibrational states within the grain‐boundary dislocation cores, as reported by by Eric R. Hoglund, Sokrates T. Pantelides, Patrick E. Hopkins, Jordan A. Hachtel, and co‐workers in article number 2208920. Density‐functional‐theory calculations of thousand‐atom supercells show that the unique environment of atoms in the dislocation cores results in new vibrational modes that are highly localized and have energies in the Restrahlen band.