Preparation And Properties Of Rare Earth Doped YF3 And L YF4 Glass-ceramics

In recent years,highly transparent oxyfluoride glass-ceramics have been extensively studied.Compared with other materials doped with rare earth,this is a new type of nanocomposite material,which is composed of fluoride nanocrystals and oxide matrix glass.Due to this composite structure,this material not only has stable structural characteristics,but also has excellent luminous properties.It has very important applications in fluorescence display,LED lighting,X-ray detectors,medical imaging and other fields.In this paper,the high-temperature melting method was used to obtain rare-earth-doped silicate glass as the matrix glass,and then the glass-ceramics containing YF₃ and LiYF₄nanocrystals were prepared by the method of secondary heat treatment.The crystallization behavior of these two types of glass-ceramics was studied by DSC,XRD,TEM,transmission spectrum and other methods;The luminescent properties of glass-ceramics have been studied through various methods including fluorescence spectrogram and lifetime decay curve;The potential of Tb³⁺doped YF₃ and LiYF₄ glass-ceramics as scintillation materials was explored by X-ray spectroscopy.The spectral properties of Ce³⁺/Tb³⁺co-doped LiYF₄ glass ceramics and the energy transfer relationship between Ce³⁺ions and Tb³⁺ions were also studied.The research content of this paper is summarized as follows:1.Preparation of Tb³⁺-doped YF₃ transparent glass-ceramics and study of its spectral properties:Highly transparent YF₃ glass-ceramics doped with Tb³⁺ions were prepared.The experiment found that the temperature of the heat treatment has a great influence on the crystallization process.The higher the temperature,the larger the size of the nanocrystals precipitated,and the transmittance of the glass-ceramics continues to decline.The research results show that when YF₃ nanocrystals are precipitated from the Tb³⁺doped matrix glass,this glass-ceramic can maintain a very high transparency while the luminous intensity is significantly enhanced under near ultraviolet and X-ray excitation.2.Preparation of Tb³⁺-doped LiYF₄ transparent glass-ceramics and study of its spectral properties:After optimizing the raw material components in the literature,high-temperature melting and proper heat treatment were used to prepare highly transparent LiYF₄ glass-ceramics doped with Tb³⁺ions.The influences of thermal treatment temperature and time on the crystallization process were studied,and the microstructure and optical properties of the samples were studied by a series of characterization methods.Studies have shown that after heat treatment and crystallization,Tb³⁺ions gradually enter the LiYF₄ nanocrystals with lower phonon energy,the PL and XEL spectral intensities are significantly enhanced,and the fluorescence lifetime is extended.3.Preparation of Ce³⁺/Tb³⁺co-doped LiYF₄ glass-ceramics and study of its spectral properties:Ce³⁺/Tb³⁺co-doped LiYF₄ transparent glass-ceramics were prepared by a method of high temperature melting and subsequent appropriate heat treatment.The crystal structure in the sample was analyzed by XRD pattern and TEM image.The emission spectra of Ce³⁺/Tb³⁺co-doped LiYF₄glass-ceramics were tested,and the energy transfer relationship between Ce³⁺ions and Tb³⁺was discussed through the emission spectra and corresponding ion energy level diagrams.