不同掺杂稀土离子对新型TiO_2基上转换发光玻璃热稳定性的影响

Study on Thermal Stability of Rare Earth Ions Co-doped Titanate Glass with Upconversion Emissions

利用气体悬浮技术,以低声子能量的重金属氧化物为基质,成功制备出了传统方法难以得到的稀土掺杂的不含氟上转换氧化物玻璃材料,分别为Ho3+/Yb3+、Er3+/Yb3+、Nd3+/Yb3+稀土离子共掺杂的La2O3-TiO2-ZrO2(LTZ)发光玻璃。利用热分析技术研究该类新型稀土掺杂TiO2基上转换发光玻璃的热稳定性,实验结果发现掺杂Ho3+离子比掺杂Er3+和Nd3+离子的La2O3-TiO2-ZrO2粉体更易生成玻璃,不同掺杂离子LTZ玻璃的热稳定性大小为:LTZH﹥LTZE﹥LTZN。同时利用多重速率扫描技术对新型稀土掺杂TiO2基上转换发光玻璃进行热分析动力学研究,采用ASTME698和Friedman两种不同的热动力学分析方法,计算出LTZH发光玻璃的析晶活化能和指前因子。随着反应进程的增加,LTZH发光玻璃的析晶活化能值先增大后减小。LTZH玻璃开始发生析晶反应时,需要获得突破一个较大的势能才能完成,这说明该类玻璃刚开始抗析晶能力比较强,随着反应的进行LTZH玻璃更容易析出晶体。通过差热分析技术对新型高性能上转换发光玻璃材料的形成能力和热稳定性研究,为该类材料的开发以及应用推广提供了测试支持。

Aerodynamic levitation method was successfully employed to prepare rare earth ions co-doped TiO2-La2O3-ZrO2 （LTZ） glasses which cannot be fabricated by conventional methods. The Hoa ＋/ Yb3 ＋ , Er3 ＋/ Yb3＋ and Nd3 ＋/ Yb3 ＋ co-doped La2O3-TiO2-ZrO2 were named LTZH, LTZE and LTZN. Differ- ential Thermal Analysis （DTA） was used to measure the thermal stability of LTZ glasses. The thermal stability of these glasses is LTZH） LTZE） LTZN. Moreover, thermal kinetic DTA-analysis of these glasses was studied at the heating rate of 5, 10, 15, 20 K/ min. The activation energy （E.） and the pre- exponential factor （logA） were obtained by means of ASTM E698 and Friedman methods. As the reaction proceeded, the crystallization activation energy value for LTZH glass increased at first and then decreased, indicating the poor crystallization ability of LTZH glass at the beginning of reaction. However, the LTZH glass was easily crystallized later on. The characterization of thermal stability of these glasses by DTA technique is useful for the development and application of these materials.