Gamma ray irradiation-induced variations in structure and optical properties of cerium/titanium-doped oxyfluoride transparent glass-ceramics

CeO₂/TiO₂-doped oxyfluoride transparent glass ceramics with a composition of 45SiO₂–20Al₂O₃–10CaO–25CaF₂ were synthesized and irradiated by gamma ray. The effects of CeO₂/TiO₂ on the structure and optical properties of the samples before and after irradiation were investigated. Doping with CeO₂ causes network depolymerization and conversion of [AlO₆] to [AlO₄], enlarging the percolation region and promoting CaF₂ crystallization. Co-doping with CeO₂/TiO₂ helps reduce the intrinsic coloring of transparent glass ceramics containing only CeO₂, and the addition of TiO₂ enhances network interconnectivity, suppressing CaF₂ crystallization. Doping with CeO₂ and/or TiO₂ improves the structural stability of transparent glass ceramics upon irradiation and maintains the optical band gap and Urbach energy constant due to the defect saturation over the irradiation dose. Doping solely with CeO₂ allows for a lower radiation-induced absorption coefficient than co-doping CeO₂/TiO₂ because of the enhanced crystallization induced by CeO₂ and balanceable light absorption of polyvalent cerium ions.