Sc2O3：Nd，Sc2O3：Yb纳米粉体的制备和光致发光

Synthesis and Photoluminescence Properties of Nanocrystalline Sc_2O_3:Nd and Sc_2O_3:Yb Powders

以反滴定共沉淀方法制备了Sc2O3:Nd、Sc2O3:Yb纳米粉体,用热重、差热分析、X射线衍射对前驱体相变及粉体结构进行了研究,并研究了其光致发光。Sc2O3:Nd、Sc2O3:Yb前躯体的热重和差热曲线分别在73℃、77℃与434℃、436℃出现了明显的热失重和吸热峰,结合XRD表明约在450℃,前驱体粉体经γ-ScOOH相转变为立方Sc2O3相。Reitveld方法精修给出Sc、O的原子坐标。结果表明,掺杂离子导致了晶格畸变。在825nm光激发下,粉体Sc2O3:Nd的1084nm主荧光峰为Nd3+的4F3/2→4I11/2跃迁;在937nm光激发下,粉体Sc2O3:Yb的1044nm主荧光峰为Yb3+的2F5/2→2F7/2跃迁。Sc2O3:Nd、Sc2O3:Yb的发光光谱表明激活离子处于较强晶场中,Stark能级分裂大,有利于降低Yb3+的激光阈值、提高激光热稳定性。

Nanocrystalline Sc2O3：Nd and Sc2O3：Yb powders were prepared by reverse-striking co-precipitation method. The phase transition and the structure of the precipitant precursor were analyzed by TG-DTA and the X-ray diffraction. Meanwhile, the photoluminescence of Sc2O3：Nd and Sc2O3：Yb powders were also studied. The results of TG-DTA show that obvious weight loss and endothermic peaks appear at 73 ℃, 434 ℃ for Sc2O3：Yb and 77 ℃, 436 ℃ for Sc2O3：Nd, respectively. According to the X-ray diffraction, it can be deduced that the precursor transforms from γ-ScOOH phase into cubic Sc2O3 phase at about 450 ℃. The atom coordinates of Sc and O are obtained by Rietveld refinement method. The doped ions lead to the distortion of lattice .The photoluminescence peak of the Sc2O3：Nd under 825 nm excitation locates at 1084 nm, which is from 4^F3/2→4^I11/2 transition of Nd^3＋, and the strongest emission peak of the Sc2O3：Yb under 937 nm excitation is at 1044 nm, which is attributed to 2^F5/2→2^F7/2 transition of Yb^3＋. The emission spectra indicate that active ions are located in a relatively strong crystal field, which leads to a large splitting of the active ions energy levels. It is beneficial to decrease the laser threshold of Yb^3＋ and improve the thermal stability of laser.