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摘要：近年来，在众多稀土功能材料当中，稀土发光材料尤其引人瞩目。因为稀土具有特殊的电子层结构，并且具有一般元素所无法比拟的光谱性质。中国的稀土应用研究中，发光材料占主要地位。稀土发光几乎覆盖了整个固体的范畴，只要谈到发光，几乎离不开稀土。稀土元素的原子具有受到外界屏蔽的并未充满的4f5d电子组态，所以有丰富的电子能级和长寿命激发态，能级跃迁通道多达20余万个，可以产生多种多样的辐射吸收和发射，构成广泛的发光和激光材料。而在稀土材料中,稀土钼酸盐发光材料具有良好的光热稳定性和化学稳定性，是一种很好的发光基质材料。但关于钼酸盐发光材料的研究却很少，并且合成方法主要是高温固相法，反应温度过高且不利于控制，而产物的发光性能一般。本文采用了有机络合物二酸配体作为添加剂水热辅助合成方法，制备钼酸盐发光材料，即Y2(MoO4)3:Ln3+( Ln3+= Eu，Tb)。文章主要探索了三种合成方案：第一种是硝酸钇和钼酸铵的配比为1:1，改变反应的pH；第二种是采用络合剂EDTA，改变硝酸钇和钼酸铵的配比，其余反应条件不变，寻找出最佳反应配比，这两个方案是来探索合成钼酸钇钾的制备条件；第三种是采用探索出的二酸体系，即丁二酸和丙二酸为配体来合成钼酸钇。之后分别将发光离子Eu3+和Tb3+掺入合成的钼酸钇当中，制备发光材料。最后将合成所得产物用XRD，SEM和荧光光谱仪等一系列方法进行表征，对材料进行形貌调控及性能研究。38702
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毕业论文关键词：水热法；钼酸盐；发光材料
The study on morphology and properties of Rare Earth Molybdate phosphors
Abstract: In recent years, rare earth luminescent material is especially impressive. Because of the special structure of the rare earth, the spectral properties of the rare earth elements are incomparable with the ordinary elements. The main status of luminescent materials is the research of rare earth application in China. Rare earth light emitting almost cover the entire solid category, as long as the luminescence, almost without the rare earth. Rare earth element atoms have to shield the outside have not been filled with the 4f5d electronic configuration, so there are abundant electron energy levels and long-lived excited state, energy transitions channels up to more than 20 million, can produce a variety of radiation absorption and emission, constitute a broad luminescent and laser materials. And in rare earth materials, rare earth molybdate luminescent material with good thermal and chemical stability is a very good light-emitting substrate material. But molybdate luminescent materials have been studied rarely, and synthetic method mainly focus on high temperature solid state method, and reaction temperature is too high and is not conducive to control the luminescent performance of products. In this paper, the hydrothermal method was used to synthetize molybdate luminescent materials with chemical formulas of Y2(MoO4)3:Ln3+ (Ln3+= Eu, Tb). This paper probes into the three synthetic plans: first,the molar ratio of yttrium nitrate and ammonium molybdate is 1:1, then control the morphology by changing the pH values of the reaction solution; second, different molar ratios of yttrium nitrate and ammonium molybdate were chosen to find out the best reaction ratio of with the chealting agent of EDTA, other conditions remain unchanged; the third is used to explore the acid system, succinic acid and malonic acid are acted as ligand to synthesize molybdenum yttrium. Then optical ions Eu3+, Tb3+ doped potassium yttrium molybdate was synthetized. Finally, the obtained products were characterized by XRD, SEM and fluorescence spectrometer, and the morphology and properties of the materials were studied.
Keywords: hydrothermal method; molybdates; luminescent materials
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