Extended defects accommodating non-stoichiometry in rutiles reduced slightly to compositions of TiO1.9966, TiO1.9979, and TiO1.9986 were seen to dissolve in situ in an electron microscope using a goniometer at temperatures of up to 1000C. This permitted the determination, as directly as possible, of the stoichiometry dependence of the dissolution temperature and hence the phase limits of non-stoichiometric TiO2-x. The defect structures formed during dissolution, and also the re-precipitation of extended defects upon cooling of the specimens to room temperature, were also studied.

Extended versus Small Defect-Equilibria in Non-Stoichiometric Rutile. I. Dissolution and Re-Precipitation of Extended Defects Observed by in situ Transmission Electron Microscopy. Blanchin, M.G., Bursill, L.A.: Physica Status Solidi A, 1984, 86[1], 101-9