The structure of a Σ5 (210) boundary in rutile was investigated by high resolution electron microscopy. The boundary was stepped with an average inclination of about 5° from the symmetrical (210) plane. The steps were associated with 1/5[210] DSC lattice dislocations accommodating a deviation of about 2° from the exact Σ5 misorientation of 53.1°, and resulting in a misorientation of 51°. The boundary topography, the location of structural units and the local symmetry were determined using pattern recognition techniques. Flat terraces between steps had a periodic Σ5 (210) structure which exhibited mirror glide symmetry. Image simulations showed best agreement with experimental images for a model structure with a rigid body shift of 0.21nm parallel, and a 0.10nm volume contraction normal to the interface. This structure requires a high density of defects or an excess of Ti ions, presumably of lower oxidation state.

HREM Analysis of Structure and Defects in a Σ5 (210) Grain Boundary in Rutile. Dahmen, U., Paciornik, S., Solorzano, I.G., Vandersande, J.B.: Interface Science, 1994, 2[2], 125-36