HAADF-STEM observations of a<i>Σ</i>13 grain boundary in α-Al₂O₃from two orthogonal directions

Abstract

Atomic structure of a Σ = 13, grain boundary in α-Al2O3 was directly observed by aberration-corrected Z-contrast scanning transmission electron microscopy. Combining observations from two orthogonal directions parallel to the grain boundary plane , 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.