纳米Y₂SiO₅：Eu～（3+）荧光粉的制备、表征与微结构研究

【作者】 俞仙妙；

【导师】 黄莉蕾；

【作者基本信息】 中国计量科学研究院 ， 测试计量技术及仪器， 2006， 硕士

【摘要】 Y₂SiO₅：RE³⁺荧光粉是一种重要的稀土化合物，其中微米多晶粉Y₂SiO₅：Tb³⁺已在显象和照明光源等高新技术中广泛应用。随着纳米荧光材料的研究兴起，发现掺稀土纳米材料的荧光特性的许多优异性能可以弥补微米体材料之不足，有文献称Y₂SiO₅：Eu³⁺的纳米粉比微米粉的发光亮度高，但有关纳米荧光粉微结构与荧光特性之间的关联未见报导。本文旨在以Y₂SiO₅：Eu³⁺纳米荧光粉作为研究对象，探讨纳米材料微结构变化与荧光特性之间的关联，以及掺杂离子类别、基质材料的组态、材料制备方法等与微结构变化之间的关系，为寻求荧光性能优异的掺稀土纳米发光材料奠定材料设计的基础。 本研究采用高分子网络凝胶法和凝胶燃烧法制备Y₂SiO₅：Eu³⁺纳米荧光粉。其中Y₂SiO₅为基质，掺入的稀土离子Eu³⁺是发光中心，还研究了共掺Gd³⁺敏化剂的影响。 本研究详细研究了所选用的两种制备方法。在高分子网络凝胶法制备中研究了PEG和PVA等高分子网络剂对最终粉体的影响，它们与钇离子形成烙合健，形成高分子有机网，限制粒子的长大。并研究了先驱液配比、PH值、水浴温度、陈化时间、烘箱温度及预烧煅烧温度等诸多因素对Y₂SiO₅：Eu³⁺纳米荧光粉晶粒大小的影响；其中烧结工艺是重要影响因素，涉及到能否制得分散较好的纳米颗粒，因此着重研究了烧结工艺对颗粒粒径的影响。已用此法制备出平均颗粒尺寸为25nm、40nm、84nm、103nm等不同粒径的纳米粉体Y₂S_iO₅：Eu³⁺。分析了影响粒径的因素，对制备粒径可控的纳米粉体进而研究其微观结构相对于体材料的变化有一定意义。用燃烧法来制备Y₂S_iO₅：Eu³⁺荧光粉未见其他报道，本研究详细研究了甘氨酸的用量、硅钇配比、水的含量、燃烧温度、煅烧温度对反应及最终产物的影响，重点研究了甘氨酸用量和燃烧温度对反应成功的影响。已申请（200510060257.7号）国家发明专利。特别是本研究打破在1250℃以下烧结不能制得X₂型Y₂S_iO₅：Eu³⁺荧光粉的禁限，而在1100℃烧结成功制取X₂型Y₂S_iO₅：Eu³⁺纳米荧光粉，文献报道在1250℃以上烧结制得X₂型Y₂S_iO₅：Eu³⁺荧光粉均为微米粉，故本研究非常有商业价值，正在准备申请有关国家发明专利。 本研究应用透射电镜（TEM）、原子力显微镜（AFM）、X射线衍射仪（XRD）、紫外分光光度计（UV）、傅立叶红外光谱仪（FT-IR）、荧光分光光度计等综合试验手段对Y₂S_iO₅：Eu³⁺纳米荧光粉进行表征，系统研究了Y₂S_iO₅：Eu³⁺纳米荧光粉的形貌、微观结构和光学性能。 X射线衍射谱分析得知样品的结构为单斜晶系，950℃时纳米晶Y₂S_iO₅：Eu³⁺已形成。并利用单斜晶系的晶格常数公式，用最小二乘法计算晶格常数、晶面间夹角和晶胞体积。根据群论，详细讨论和分析了Y₂S_iO₅的晶体场，结合对称操作，绘出的X₂型和X₁型Y₂S_iO₅晶体结构图，计算了Y1和Y2格位的配位数、Y1和Y2格位近邻0^2-离子的距离和键角，第二近邻氧配位数及各配位键的键长键角等数据，并与EXAFS数据进行对比。对X₁型和X₂型Y₂S_iO₅：Eu³⁺作对比分析，发现X₂型的Y1和Y2格位的配位数分更多还原

【Abstract】 Y₂SiO₅:Eu³⁺ phosphor is an important rare earth compounds, and the bulk material has been used in the advanced technique field of raster display, illuminating lamps.With increasing research interests of nano-phosphor, it has been found that nano-phosphor doped with doped with RE³⁺ ions have many perfect properties which can complement the disadvantages of bulk materials. It has been reported that nanocrystalline Y₂SiO₅:Eu³⁺ has higher fluorescence intensity compared with bulk materials. However, relationships between the microcosmic structure and fluorescent properties have not been reported.In this paper, it is intended to research the relationships between the microcosmic structure of nanocrystalline Y₂SiO₅:Eu³⁺ and the optical properties. It is also discussed that many factors, such as, the kinds of doped ions, configuration of host materials and preparation techniques, have influences on the microcosmic structure of nano-materials. And it is hopeful to seek after theoretical basis for RE³⁺ doped nano-phosphors with perfect properties.Nanocrystalline Y₂SiO₅:Eu³⁺ has been prepared by the polymer-net gel process and the gel-combustion synthesis. The powder Y₂SiO₅ is the host and the Eu³⁺ ions are luminescence centers. The Gd³⁺ ions are chosen for sensitive activators and its influence on optical property of Y₂SiO₅:Eu³⁺ has been researched.The two chosen preparation techniques have been researched in detail. It has been found that some polymer-net reagents, such as PEG and PVA have effects on the final powder. The reagents and Y³⁺ ions can form irons gathers bond, and then form organic-net which restrict grains to grow bigger. It is found that many factors, such as, the ratio of the precursor, PH value, time of water bath and slating, temperature of oven and pre-calcination, have influences on the grain size of nanocrystalline Y₂SiO₅:Eu³⁺. Among them calcination technique is the most important effect which decides the good scattered nanocrystalline can be obtained or not and it is researched in detail. Nanocrystalline Y₂SiO₅:Eu³⁺ with different average grain sizes, such as, 25nm,40nm,84nm,103nm have been prepared by this technique and grain size affected factors has been analyzed. It is significative to prepare nanocrystalline with controllable grain size and research its microcosmic structure further.It is not reported that Y₂SiO₅:Eu³⁺ can be prepared by combustion synthesis heretofore. In this paper, influences of different factors, such as quantity of glycine, water of the precursor, ratio between silicon and yttrium, burning temperature and calcination temperature on the grain size of the nanocrystalline have been researched, it is discussed particularly that the quantity of have influences on the final outcome, especially the quantity of glycine and calcination temperature. The national更多还原