Reduction effects in rutile induced by neutron irradiation

Reduction effect in rutile induced by neutron irradiation and its post-annealing experiment has been investigated. Rutile TiO2 (1 1 0) specimens were cut from the same crystal, and irradiated with high-fluence (1x1019 cm-2) neutron irradiation, then annealed in vacuum and oxidizing atmosphere at different temperatures, respectively. After irradiation, rutile shows deep dark-blue color. After oxidization, it becomes transparent again. But annealed in vacuum, the color of irradiated sample keeps invariable. By means of UV-VIS-IR, XPS, XRD and AFM, samples were investigated before and after irradiation, as well as after annealing. The results show that neutron irradiation induces O2- ions sputtering and Ti4+ ions reduce to Ti3+, Ti2+, even Ti+, and leads to metallization tendency, and the reduction of Ti4+ presents depth-distribution. Especially surface morphology shows step pattern and polycrystalline structure because of insufficiency of O2- ions