Investigation On Preparation Technology And Luminescent Property Of The Oxyfluoride Glasses Doped With Rare Earth Ions

Compared with single crystals and ceramics, the scintillating glasses possess many merits such as easy shaping, chemical composition adjusting, large size and low production cost, which enable the glasses to become an attractive scintillator matrix. However, it is not satisfied with the performance of the scintillating glasses developed in the density, luminescence efficiency, light yield, radiation hardness, and so on.In this paper, the luminescence of rare earth ions and the effect of glass matrix on the luminescence of rare earth ion were introduced systematically, and the progress of the scintillating glasses was summarized. New Ce3+, Tb3+ single-doped and co-doped Li-Ba-Al-Si, Li-Ba-Gd-Al-Si oxyfluoride glasses were synthesized by the traditional melt quenching technology with the low poisonous and cheap BaF2 as the fluorine source. The X-ray diffraction, infrared spectrum, differential scanning calorimetry thermal analysis, transmission spectrum, fluorescence spectrum and fluorescence decay spectrum were operated in order to investigate the structure and luminescent performance of these oxyflroride glasses. Some important results and conclusions have been obtained, which can provide some new ideas and choices for developing new scintillating glasses.Infrared spectra of Ce3+, Tb3+ single-doped and co-doped Li-Ba-Al-Si, Li-Ba-Gd-Al-Si oxyfluoride glasses indicate that the glass network is constituted with [SiO4] and [AO4] by the connection of vertex angle oxide ions with the tetrahedra, and a part of F- ions probably enter the glass network. These glasses are suitable matrix materials to prepare the scintillation glasses with excellent performance because of their good thermostability, high (Ts-Tg) value, short ultraviolet absorption edge that is advantageous for the transmission of emission light.The luminescent performance has been investigated in the Tb3+, Ce3 single-doped Li-Ba-Al-Si oxyfluoride glasses. Tb3+ions launch blue green color fluorescence with millisecond level luminous decay time. The resonance energy transfer can take place between the excited Tb3+ ion and the neighboring unexcited Tb3+ ion. With the increase of the concentration of Tb3+ ion, the probability of 5D3?7FJ, transition reduces, and that of 5D4?7FJ transition increases, resulting in the remarkable enhancement of the blue green light emission intensity. Ce3+ions launch very strong blue violet light with nanosecond level decay time. The emission intensity of Ce3+ ions ascends firstly and then decreases with the increase of the content of Ce3+ ions.Ce3+, Tb3+ co-doped Li-Ba-Al-Si oxyfluoride glasses mainly launch the blue green light from excited Tb3+ ions. Ce3+ion could sensitize Tb3+ ion for the Ce3+?Tb3+ energy transfer. As a result, the luminous intensity and decay time of Tb3+ ion in Ce3+, Tb3+ co-doped Li-Ba-Al-Si oxyfluoride glasses are higher than that in Tb3+ single-doped Li-Ba-Al-Si oxyfluoride glasses.Gd3+ions mainly launch ultraviolet light of 314 nm in the Li-Ba-Gd-Al-Si oxyfluoride glasses. The emission intensity of Gd3+ ions increases with the decrease of Gd2O3 content in glasses. After Ce3+ ions are introduced into Li-Ba-Gd-Al-Si oxyfluoride glasses, those resultant glasses mainly launch blue violet light from the excited Ce+ ions. The luminous intensity of Ce3+ions in the glasses, which ascends firstly and then decreases with the increase of the Gd2O3 content, is lower than that in Ce3+-doped Li-Ba-Al-Si oxyfluoride glasses with the same Ce3+ concentration for the competitive absorb between Gd3+ and Ce3+ ions.Tb3+ single-doped Li-Ba-Gd-Al-Si oxyfluoride glasses mainly launch blue green light from the excited Tb3+ ions. With the increase of the Gd2O3 content, the luminous intensity of Tb3+ ions increases, and that of Gd3+ ions is weaken. Gd3+ion could sensitize Tb3+ ion for the presence of Gd3+?Tb3+ energy transfer, resulting in that the luminous intensity of Tb3+ ions is higher than that in Tb3+-doped Li-Ba-Al-Si oxyfluoride glasses with the same Tb3+ concentration.In the Ce3+, Tb3+ co-doped Li-Ba-Gd-Al-Si oxyfluoride glasses; the luminescence mainly comes from the excited Ce3+ and Tb3+ ions. Gd3+?Ce3+, Gd3+?Tb3+and Gd3+?Ce3+?Tb3+ effective energy transfer could take place among Gd3+, Ce3+ and Tb3+ ions. The luminous intensity of Tb3+ ions in these oxyfluoride glasses, which decreases with the increase of Gd2O3 content, is higher than that in Tb3+-doped Li-Ba-Gd-Al-Si oxyfluoride glasses.