Polarization and ESR studies of thermally pretreated γ-irradiated TiO2

Pellets of TiO₂ thermally pretreated at 450 and 540°C and -irradiated were polarized by d. c. field. The depolarization curves were resolved into different first order components having two and three depolarization constants. By heating the polarized pellets the Current Glow Peak curves were recorded where there were only two peaks around 65 and 400°C in case of pellets heated at 450°C and heated at 540°C and irradiated; and one more additional peak around 20°C in case of pellets heated at 540°C and heated at 450°C and irradiated thereon. In addition to those signals of O ₂ ^– and Ti³⁺ reported earlier there were distinctly four more, signals at g 1.933 and g 2.03, 2.036 and 2.043 appeared in case of samples heated at 540°C and heated at 450°C and irradiated thereon. The signal at g1.933 is attributed to Ti³⁺ ions in new phase Ti₄O₇ developed in heating at 540°C or due to irradiation and the rest of the signals are due to O _2ad ^– or O _ad ^– over the new phase near anion vacancy created.