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稀土磷钒酸盐微纳米发光材料的制备及性能研究

时间:2017-02-13 12:44来源:毕业论文
论文采用水热法合成出了结晶度很高的球形YP0.3V0.7O4:Eu/Dy微纳米颗粒,利用XRD、荧光光谱和SEM等手段对所合成的样品进行了表征。用EDTA为络合剂,得到的产物呈现出类球型结构的YP0.3V0

摘要:本论文采用不同的有机配体,与稀土离子络合,构筑稀土有机配合物前驱体,利用水热法合成具有新型结构和形貌的稀土磷钒酸盐发光材料,然后掺杂不同的稀土离子调节稀土磷钒酸盐的发光性能,并且研究其发光性能。论文采用水热法合成出了结晶度很高的球形YP0.3V0.7O4:Eu/Dy微纳米颗粒,利用XRD、荧光光谱和SEM等手段对所合成的样品进行了表征。用EDTA为络合剂,得到的产物呈现出类球型结构的YP0.3V0.7O4。此外,研究发现:不同EDTA的量所制备的稀土磷钒酸盐,其形貌也各有差异,当EDTA为2-4 mmol时, 产物呈现出纳米片状结构堆簇的类球型结构。而当EDTA量为6– 8 mmol时, 产物也是类似于球状结构,但是表面形貌比较光滑。使用丙二酸作为络合剂时,所得的材料形貌较好,当pH=4,得到了具有球状结构的稀土磷钒酸盐。对其发射光谱进行分析,结果表明Eu3+的发射峰光谱图中观察到来自5D0→7F1、7F2、7F3和7F4的跃迁带。其中位于616nm5D0→7F2带(红色荧光)十分强。掺杂Dy3+的发光材料的发射光谱图中观察到来自于Dy3+特征发射峰,分别为4F9/2 → 6H15/2 (483nm, 蓝光)和4F9/2 → 6H13/2 (573 nm, 黄光)。研究发现,Dy3+的最佳掺杂浓度为1mol%,而Eu3+的最佳掺杂浓度为7 mol%。这可能是因为在同种基质中,Dy3+之间的相互作用较为活跃,易造成能量以非辐射形式损失,而使发光猝灭,猝灭浓度较低,Eu3+之间的相互作用较为迟钝,猝灭浓度较大。5710
关键词:纳米发光材料; 水热法;磷钒酸盐;Eu3+;Dy3+
Preparation and Properties of rare earth phosphate vanadate micro and nano light-emitting materials
Abstract:In this paper, different organic complexes with rare earth ion were doped to adjust the morphology and structure of YP0.3V0.7O4 using the hydrothermal method. These as-synthesized products were characterized by X-ray diffraction, scanning electron microscopy, and photoluminescence spectroscopy. The results showed that when added different amount of EDTA, the products presented different morphology. When the amount of EDTA is 0 mmol, the products were irregular nanoparticles. While the amount of EDTA was from 2 to 4 mmol, the products showed sphere-like morphology, which were assembled by numerous nanoflakes. And when the amount of EDTA was from 6 to 8 mmol, the products were also sphere-like morphology, but we could not observe the surface morphology and structure. Obviously, it was found that EDTA played a key role in the formation for sphere-like YP0.3V0.7O4. And malonic acid also benefits the control on the morgphology of YP0.3V0.7O4, but the condition of reaction should be at the optimum pH of 4, the product can be obtained with the sphere – like morphology. Additionally, the luminescent spectra have shown that YP0.3V0.7O4:Eu3+showed strong red emissions, and the emission spectra consisted of the characteristic lines from low energy level 5D0 to 7FJ (J = 1, 2, 3, 4) of Eu3+. Besides this, it was found that 5D0-7F2 transition was the strongest in intensity compared to the other transitions. The emission spectra of YP0.3V0.7O4:Dy3+ had two strong and broad bands at 483 and 573 nm, respectively. These emissions corresponded to the characteristic emission of Dy3+ due to the transitions of 4F9/2 → 6H15/2 and 4F9/2 → 6H13/2, respectively. Finally, the doping concentration has been discussed. The optimum doped concentration of Dy3+ was 1 mol% and that of Eu3+ was 7 mol%. This is possibly because that the the cross – relaxation between two Dy3+  ions is more active than that between two Eu3+ ions, which quench the luminescence of rare earth ions.
Keywords:Luminescent Nanomaterials;hydrothermal method;( P,V)O43-;Dy3+; Eu3+.
目录
1引言    1
1.1课题研究背景    1
1.2课题研究的现状    2 稀土磷钒酸盐微纳米发光材料的制备及性能研究:http://www.youerw.com/huaxue/lunwen_2864.html
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