Transmission electron microscope observations of slightly reduced rutile

Observations of rutile TiO2–x single crystals with x ≦ 0.003 have been made by transmission electron microscopy. Crystallographic shear planes are not observed in crystals quenched from the reduction temperature (1323 K) but can appear after annealing at lower temperatures. A mechanical deformation preliminary to the reduction process is shown to activate the production of the crystallographic shear planes.