Atomic structure of a Σ = 13, (10•4) 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 ([1¯2•0] and [¯20•1]), the three-dimensional atomic configuration of the grain boundary core region could be determined, and proves to be in a good agreement with the stable boundary structure predicted by first-principles calculations.

HAADF-STEM Observations of a Σ13 Grain Boundary in α-Al2O3 from Two Orthogonal Directions. S.Azuma, N.Shibata, S.D.Findlay, T.Mizoguchi, T.Yamamoto, Y.Ikuhara: Philosophical Magazine Letters, 2010, 90[8], 539-46