Alumina bicrystals with low-angle and near-Σ3 <00•1> tilt grain boundaries were prepared via diffusion bonding. The resultant grain-boundary structures were investigated by using high-resolution transmission electron microscopy, and the grain-boundary energies were estimated by using theoretical calculations. It was found that partial dislocations with Burgers vectors of 13<10•0> type were located periodically in the boundaries and that a stacking fault was present between pairs of partials in such boundaries. The length of the stacking fault decreased with increased misorientation angle, as predicted by the theoretical calculations. In the case of a near-Σ3 grain boundary, dislocations with a Burgers vector of 13<1¯1•0> were arrayed periodically along the boundaries. These boundaries did not contain stacking faults. The spacing between the dislocations decreased with increasing deviation from the exact-Σ3 boundary tilt angle of 60°.

Dislocation Structures of Low-Angle and Near-Σ3 Grain Boundaries in Alumina Bicrystals. Y.Ikuhara, H.Nishimura, A.Nakamura, K.Matsunaga, T.Yamamoto, K.P.D.Lagerlöf: Journal of the American Ceramic Society, 2003, 86[4], 595-602