HAADF-STEM observations of a ∑13 grain boundary in α-Al_2O_3 from two orthogonal directions

摘要

Atomic structure of a ∑13, (1014) grain boundary in α-Al_2O_3 was directly observed by aberration-corrected Z-contrast scanning transmission electron microscopy. Combining observations from two orthogonal directions parallel to the grain boundary plane ([1210]) and ([2021)], the three-dimensional atomic configuration of the grain boundary core region can be determined, and proves to be in a good agreement with the stable boundary structure predicted by first-principles calculations.