Investigation On The Probe Property Of Eu ³⁺ And Fluorescence Property Of Oxy-fluoride Glasses Doped With Rare Earth Ions

Eu³⁺ doped, Bi³⁺/Eu³⁺ co-doped, Yb³⁺/Eu³⁺ co-doped borosilicate glasses and Yb³⁺/Er³⁺ co-doped oxy-fluoride glasses have been prepared by high temperature sintering. The energy transfer between Bi³⁺ and Eu³⁺ was discussed, and based on the emission spectra of Eu³⁺, the effect on the micro-environment around Eu³⁺ with Bi³⁺ dopant was studied via Judd-Ofelt theory. The influence of Bi³⁺ on the multi-phonon non-radiation probability of Eu³⁺ was discussed through Miyakava-Dexter theory and phonon sidebands spectra. The results show that Bi³⁺ can well sensitize Eu³⁺, and when Bi³⁺ are doped the covalent property around Eu³⁺ becomes stronger with the symmetry getting smaller, which enhances the electric-dipole moment transition of Eu³⁺. The multi-phonon non-radiation probability of Eu³⁺ also increases with the certain concentration of Bi³⁺, which reduces the emission intensities of Eu³⁺.Then the effect on the local site of Eu³⁺ after Yb³⁺ was doped was discussed through the energy split in the crystal field of borosilicate glasses and the fluorescence spectra of Eu³⁺. And the ratio between ⁵D₀-⁷F₂ electric-dipole moment transition intensity and ⁵D₀-⁷F₁ magnetic dipole transition intensity was defined as R to characterize the influence of Yb³⁺ on the micro-environment around Eu³⁺. The energy transfer between Yb³⁺ and Eu³⁺ was also studied. The results show that the dopant of Yb³⁺ can enhance the ionicity and the symmetry around Eu³⁺. The Yb³⁺ dopant can also induce Eu³⁺ to happen transition referring to virtual energy level.At last, the influence of annealing process on the up-conversion fluorescence properties of Yb³⁺/Er³⁺ co-doped oxy-fluoride glasses was investigated, and the up-conversion fluorescence spectra under different power of pump light and different temperature were measured. The energy transfer between Yb³⁺ and Er³⁺ and the temperature properties of samples before and after annealing was discussed, and the application of these samples in the temperature sensor was investigated. The results show that the up-conversion fluorescence intensities of sample after annealing significantly become stronger. Before and after annealing, Yb³⁺/Er³⁺ co-doped oxy-fluoride glasses up-conversion emission at 523nm, 547nm and 667nm all belong to two-photon process. The highest working temperature of Yb³⁺/Er³⁺ co-doped oxy-fluoride glass after annealing is about 823K, and it can also increase. When the temperature is 373K, the high temperature sensor sensitivity is about 0.0047K-1. The highest working temperature of sample not annealing is 803K, and when the temperature is 423K, the sensitivity is the biggest, about 0.0045K-1. The high temperature sensor sensitivites of this series samples are bigger than those reported before, implying that they have good prospect in making high temperature sensor.