Studies On Preparation And Luminescence Mechanisms Of Ce³⁺/Tb³⁺ Doped Silicate Glass Ceramics Containing Fluoride Nanocrystals

Oxyfluoride glass ceramic is a new functional material possessing excellent thermal, mechanical, optical and chemical properties. It has a wide range of applications such as in the field of advanced defense technology and microelectronics because of its advantages of both the oxide glass and fluoride crystal.In this thesis, rare earth ions doped glass ceramics containing different fluoride nanocrystals in silicate glass matrix were prepared and the thermal properties, ceramics species, controlled precipitation of nanocrystals, optimum doping concentration of the rare earth ions and fluorescence lifetime of the glass ceramics were investigated through differential analysis, X-ray diffraction, transmission electron microscopy, X-ray spectroscopy, fluorescence spectroscopy and other methods.Tb3+ singly doped transparent oxyfluoride glass ceramics containing MF2(M=Ba, Sr) nanocrystals were prepared. The results show the emission intensity of glass ceramics increased significantly after the precipitation of MF2(M=Ba, Sr) compared with the as-made glass and the glass ceramics maintain high transparency at the same time. Under X-ray excitation, the glass ceramics emit intense green light. Thus it is a potential glass scintillator material.Ce3+ singly doped transparent oxyfluoride glass ceramics containing Ba F 2 nanocrystals were prepared. Ce ions exist mainly in the form of Ce3+ in reduction atmosphere, and the optimal doping concentration of Ce3+ in the glass is 1 mol%. Under X-ray excitation, Ce3+ exhibits its characteristic blue broadband emission.Ce3+ singly doped transparent oxyfluoride glass ceramics containing Li YF4 nanocrystals were prepared. The major status of Ce is Ce3+ because of the using of reduction atmosphere, the introducing of suitable Ce3+ valence and the optimizing of glass component. The fluorescence of Ce3+ was enhanced in the glass ceramic. The glass ceramic has a certain content of Li+ and a short decay time at the level of nanosecond. This study could inspire the exploration on glass scintillators for thermal neutron detection.Ce3+/Tb3+ codoped transparent oxyfluoride glass ceramics containing Ba F2 nanocrystals were prepared. The results show that the energy transfer between Ce3+ and Tb3+ occurred and the energy transfer efficiency increased monotonously wit h the increasing doping concentration of Tb3+. The CIE chromaticity coordinates indicate that they are potential materials using for white light LED.