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采用Gd_2O_3,Yb_2O_3,Er_2O_3,HNO_3,CO(NH_2)_2和C_(12)H_(25)SO_4Na为实验原料,通过水热法合成了纳米Gd_2O_3:Yb~(3+),Er~(3+)上转换发光粉体。通过X射线衍射(XRD)、差示扫描量热-热重分析(DSC-TGA)、傅里叶变换红外光谱(FT-IR)、透射电子显微镜(TEM)和上转换发射光谱(UCL)等对样品进行表征。研究结果表明:CO(NH_2)_2与Gd~(3+)离子的摩尔比m影响前驱体的组成,当m=4时,前驱体是由晶态的Gd_2(CO_3)_3·xH_2O构成。该前驱体在空气气氛下800℃煅烧2h可获得单相的Gd_2O_3纳米粉体,粉体呈近球状,平均粒径约为30~40nm。上转换发光光谱表明,在980nm波长红外光激发下,Gd_2O_3:Yb~(3+),Er~(3+)的主发射峰位于664nm波长处,呈红光发射,对应于Er~(3+)的~4F_(9/2)→~4I_(15/2)跃迁。在波长为539nm和562nm附近呈现绿光发射,分别对应于Er~(3+)的~2H_(11/2)→~4I_(15/2)和~4S_(3/2)→~4I_(15/2)跃迁。Er~(3+)的猝灭浓度为1%。800℃煅烧合成的Gd_2O_3:Yb~(3+),Er~(3+)纳米粉体的上转换发光机制为双光子模型,而1 200℃煅烧合成的Gd_2O_3:Yb~(3+),Er~(3+)纳米粉体的上转换发光机制则为三光子模型。
(Gd 2 O 3: Yb 3+, Er 3+) were synthesized by hydrothermal method using Gd 2 O 3, Yb 2 O 3, Er 2 O 3, HNO 3, CO (NH 2) 2 and C 12 H 25 SO 4 -Na as raw materials. Up converter luminous powder. The microstructure and mechanical properties were characterized by XRD, DSC-TGA, FT-IR, TEM and UCL The samples were characterized. The results show that the molar ratio m of CO (NH_2) _2 to Gd ~ (3 +) ions affects the composition of the precursor. When m = 4, the precursor is composed of crystalline Gd_2 (CO_3) _3 · xH_2O. The precursor calcined at 800 ℃ for 2h in the air can be obtained single-phase Gd_2O_3 nano-powder, the powder was nearly spherical, the average particle size of about 30 ~ 40nm. The up-conversion luminescence spectra show that the main emission peak of Gd_2O_3: Yb ~ (3 +) and Er ~ (3+) is at the wavelength of 664nm under the excitation of 980nm wavelength infrared light, corresponding to Er ~ (3+ ) ~ 4F_ (9/2) → ~ 4I_ (15/2) transitions. At the wavelength of 539nm and 562nm near the green light emission, corresponding to Er ~ (3 +) ~ 2H_ (11/2) → ~ 4I_ (15/2) and ~ 4S_ (3/2) → ~ 4I_ / 2) transition. Er ~ (3 +) quenching concentration of 1%. The upconversion luminescence mechanism of the synthesized Gd_2O_3: Yb ~ (3 +) and Er ~ (3+) nanopowders synthesized at 800 ℃ is a two-photon model and the synthesized Gd_2O_3: Yb ~ (3 +), Er The upconversion luminescence mechanism of ~ (3 +) nanopowders is a three-photon model.