纳米Yb:LuScO_3的制备和发光  

Preparation and Luminescence of Nanometer Yb:LuScO_3

作　　者：丁丽华[1] 张庆礼[1] 刘文鹏[1] 邵淑芳[1] 肖进[1] 殷绍唐[1] 

机构地区：[1]中国科学院安徽光学精密机械研究所晶体材料研究室,安徽合肥230031

出　　处：《发光学报》2008年第5期875-878,共4页Chinese Journal of Luminescence

基　　金：国家自然科学基金资助项目(50772112)

摘　　要：采用液相共沉淀方法,制备了纳米材料Yb:LuScO3。X射线衍射分析结果表明,它的晶格参数为a=1.0126nm,粒度为50nm。在937nm光激发下,发射谱带很宽,发射峰分别位于976,1037,1085nm。通过漫反射吸收光谱,确定零吸收线在976nm处,能级分裂达1029cm-1,表明它的晶场分裂比较大。Yb^3＋ is a good active ion. It has the simplest level structure, consisting of only two muhiplets ^2F7/2 and ^2F5/2, which results in several advantages, such as no excited state absorption, no more up-conversion , and low quantum defect able to reduce the thermal loading. In addition, the longer fluorescence lifetime （about 1 ms） is propitious to store energy and the broad emission band allows the generation of high power laser pulse. But Yb^3＋ can Only operate in a quasi-three level scheme. The terminal state of laser emission is very close to ground state, which results in high thermal population of the laser terminal state and strong reabsorption at the emission wavelengths, and high laser pumping threshold. In order to limit thermal population of the terminal level, a relatively strong crystal field increasing the Stark-splitting of the Yb^3＋ ground manifold as large as possible is expected. In our experiment, we discover that Yb^3＋ has bigger stronger Stark-splitting in the crystalline field of LuScO3. We take ammonia as precipitator, Yb2O3, Sc2O3 and Lu2O3 as starting materials to prepare Yb： LuScO3 precursor by co-precipitation method. We obtained Yb： LuScO3 nano-polycrystal- line powders by sintering the precursor at 1 500 ℃. X-ray powder diffraction indicated that the polycrystalline Yb： LuScO3 belongs to the cubic phase, space group Ia3. Its lattice parameter a is 1. 012 6 nm, calculated by the least square method, and its size is about 50 nm. When excited at 937 nm, the strongest emission peaks of Yb： LuScO3 are at 976 nm and 1 037 nm, the weaker peak at 1 085 nm. According to its emission and absorption spectra, the energy structure of Yb^3 ＋ is determined. The overall splitting value 2 of F7/2 is 1 029 cm^-1 , which is larger than 785 cm^-1 of Yb： YAG. By comparison to emission spectrum with Yb： YAG, the emission peaks move to longer wavelength and the emission spectrum band is very wide, which advantages to decrease laser threshold and improves laser efficiency. In addi

关 键 词：LuScO3 共沉淀法 发光 纳米粉体 

分 类 号：O482.31[理学—固体物理]