High-resolution electron microscopy, in conjunction with controlled specimen preparation procedures, has enabled the nature and structure of the small defects existing within the non-stoichiometric phase TiO2-x (x = 0 to 0.01) to be investigated. In particular, the precipitation of pairs of crystallographic shear planes and their subsequent separation was observed. The atomic mechanisms involved in crystallographic shear plane nucleation and growth and the eventual evolution to an ordered crystallographic shear structure were elucidated by using linear cationic interstitial defect structural models. The results emphasized the decisive influence that cooling history had upon the microstructures observed at room temperature.

Precipitation Phenomena in Non-Stoichiometric Oxides. I. Pairs of Crystallographic Shear Planes in Reduced Rutiles. Blanchin, M.G., Bursill, L.A., Smith, D.J.: Proceedings of the Royal Society A, 1984, 391[1801], 351-72