Preparation And Luminescence Properties Of Eu³⁺ And Tm³⁺ Doped Transparent Glass-ceramics Containing NaY（MoO₄）₂

Luminescent materials doped with rare earth ions play an important role in solid-state color rendering and solid-state lighting.A series of Eu³⁺doped,Tm³⁺-Eu³⁺co-doped,Eu³⁺-Tm³⁺-Dy³⁺tri-doped transparent glass ceramics were prepared by the melt crystallization.The differential scanning calorimetry（DSC）curves of the precursor glass doped with rare earth ions were analyzed,and 10℃was selected as the gradient to conduct heat treatment on the precursor glass of each system in the temperature range of640℃-670℃,630℃-670℃and 650℃-680℃,respectively.The obtained X-ray diffraction（XRD）data of the glass ceramic samples showed that the crystal phase precipitated in the glass ceramics was NaY（MoO₄）₂,and the doping rare earth ions did not change the crystal phase.The appropriate heat treatment temperature was select by comparing the relative intensity of the XRD diffraction peaks and crystallinity of the samples at different heat treatment temperatures.The microscopic morphology of glass ceramics was observed by scanning electron microscope（SEM）,and the influence of heat treatment time on the distribution,size and quantity of crystal grains was discussed.Combining XRD,SEM and light transmittance curves to determine the optimum heat treatment time,and finally get the optimum heat treatment conditions of each system glass ceramics were 660℃/3 h,660℃/2.5 h,670℃/2.5 h,respectively.Spectral analysis was performed on the rare earth ions doped glass ceramics to study their luminescence properties.The appropriate excitation wavelength was selected through the excitation spectrum and the attribution of each excitation peak was discussed.Comparing the emission peak intensities of glass ceramics doped with different ion concentrations to discuss the optimum doping concentration.Combined with theoretical calculations,the reason for the concentration quenching,the energy transfer mechanism and energy transfer efficiency were studied.The chromaticity coordinates of rare earth ions doped glass ceramics were calculated by CIE software.The chromaticity coordinates of1.8%Eu³⁺doped,0.4%Tm³⁺-1.3%Eu³⁺co-doped and 1.5%Eu³⁺-0.4%Tm³⁺-1.1%Dy³⁺tri-doped glass ceramics were（0.6337,0.3635）,（0.2778,0.1893）,（0.3611,0.2919）,respectively.The results show that Eu³⁺,Tm³⁺,Dy³⁺doped transparent glass ceramics have potential applications in solid-state lighting and solid-state color rendering.