Symmetrical tilt grain boundaries on the (10•0), (¯21•2) and (01•8) planes in the α-phase were investigated by performing combined high-resolution transmission electron microscopy and spatially resolved energy dispersive X-ray analyses. Bicrystals were produced by diffusion-bonding under ultra-high vacuum, and Y was introduced before bonding. The prismatic twin had a bulk-like grain boundary structure and did not accommodate any Y at the grain boundary. The Y at the Σ17 (¯21•2) and Σ37 (01•8) grain boundaries changed the grain-boundary structure and the content of other impurities.

Structure and Chemistry of Symmetrical Tilt Grain Boundaries in α-Al2O3 - Bicrystals with Y at the Interface. T.Gemming, S.Nufer, W.Kurtz, M.Rühle: Journal of the American Ceramic Society, 2003, 86[4], 590-4