【摘要】 研究了Eu3 + 掺杂铌磷与铌硅系列玻璃的发射光谱 ,声子边带谱及5D0 能级寿命 ,计算了样品的强度参数。随着Nb2 O5浓度的增加 ,Eu—O键强增大 ,共价性增强 ,Eu3 + 的局域环境对称性降低 ,电 声子耦合增强 ,5D0 能级的无辐射过程加快 ,寿命变短 ,温度猝灭加剧。研究了从 77～ 6 90K铌磷与铌硅系列玻璃中Eu3 + 离子在 488nm激光激发下的变温荧光发射特性 ,求出了温度猝灭速率。分析了发光强度增强与减弱的原因 ,即热布居与无辐射过程随温度的变化关系 ,研究了谱线宽度与峰值位置随温度的变化关系。更多还原

【Abstract】 Series of niobate-phosphate and niobate-silicate glasses doped with Eu 3+ ions were prepared. The emission, phonon-side band spectra and fluorescence lifetimes of these glasses were studied and the intensity parameters Ω 2 of Eu 3+ were obtained. The temperature-dependence of emission intensity of the Eu 3+-ion in these niobate glasses was investigated. The temperature-quenching rates were determined. The results indicate that in niobate glasses, as the concentration of Nb 2O 5 increases, the covalence becomes strong, the symmetry becomes low and the electron-phonon coupling strength becomes strong, thus the lifetimes become short, the nonradiative transition processes and the temperature-quenching become strong. The temperature-dependent behavior of the Eu 3+ ion was studied in various niobate glasses. The variation of the emission intensity of Eu 3+ with temperature was attributed to two factors, the thermally excited emission from 7F 2 to 5D 2 and the temperature-quenching effect. The former tends to cause the intensity of Eu 3+ increase with temperature, while the later tends to cause the intensity decrease. The temperature-quenching rates in various glasses were obtained. They increase with the increasing concentration of Nb 2O 5. The temperature-dependencies of the peak energies and the line widths of 5D 0→ 7F J(J=0,1) were experimentally determined.更多还原