【作者】 德格吉呼；

【导师】 秦伟平；

【作者基本信息】 中国科学院研究生院（长春光学精密机械与物理研究所） ， 凝聚态物理， 2006， 博士

【摘要】 低维纳米结构材料特有的光、电、磁和机械性能,在纳米器件和功能材料等诸多领域具有潜在的应用前景。众所周知,它们的这些性质与其结构、尺度、形貌和尺寸的依赖性非常大。因此,研究纳米结构材料形貌对其物理性质的影响是本论文的宗旨。由于稀土离子光谱学能够给出材料中微环境的改变对发光中心性质影响的信息,因此光谱学方法已经成为探索研究基质材料物理性质的一种重要手段。本论文成功地合成Yb³⁺/Er³⁺共掺杂的Y₂O₃纳米结构和六角形氟化镧纳米晶,Yb³⁺/Tm³⁺共掺杂的氟化钇和氟化镧纳米片,Eu³⁺掺杂的氟化钡微纳米棒等材料。此外,我们用光谱学方法研究了其结构和性质,如上转换荧光、选择激发、傅立叶红外光谱等等。下面更详细地介绍我们的工作:1.我们用水热法合成了Yb³⁺/Er³⁺共掺杂的立方Y₂O₃纳米管、纳米球和纳米片。此三种纳米结构具有很强的上转换发光特性。我们通过红外光谱和荧光光谱分别观察了荧光性质和荧光衰减特性。随着纳米管、纳米球和纳米片的变化OH^-基团对其发光性质是影响非常大。研究表明具有高振动频率的OH^-基团对它们的发光具有淬灭作用。2.我们用简单的水热法合成了尺寸比较小,分散性和结晶性较好的六变形LaF3:Yb³⁺,Er³⁺纳米颗粒。利用XRD测定样品的结构,TEM观察确定样品的尺寸和形貌,荧光光谱分析得知此样品为发纯绿光的理想材料,有望在生物识别上获得应用。3.我们合成了Yb³⁺/Tm³⁺掺杂浓度相同的不同基质氟化物材料。经上转换发光的研究发现小尺寸的片状结构氟化物材料为比较理想的紫外上转换发光材料。4.我们用微乳法调节的溶剂热法合成了掺铕的BaF₂:Eu微米棒和纳米棒。通过激光选择激发实验来确定了Eu³⁺离子在微米棒中只仅占一个格位。更多还原

【Abstract】 Low-dimensional nanostructured materials have sparked a worldwide interest due to their unique electronic, optical, and mechanical properties and their potential applications in nanodevices and functional materials. It is known that structure, dimension, shape and size have important effect on the properties of low-dimensional nanomaterials. However, how the morphology of a nanostructure to determine its physical properties has been unknown until present days.As a micro structural probe a lanthanide ion can give us plentiful information about the local structure by spectroscopy. Therefore, the main aim in my thesis’job is to synthesize some RE ions doped nanostructures with special morphologies and to investigate their physical properties by RE spectra. In order to achieve this goal, we synthesized Yb³⁺/Er³⁺ co-doped cubic Y2O3 nanostructures and hexagonal lanthanum fluoride nanocrystals, Yb³⁺/Tm³⁺ co-doped yttrium fluoride and lanthanum fluoride nanoshees, Eu³⁺ doped barium fluorides and so on. Furthermore, their structural properties were investigated by using spectral methods, such as upconversion fluorescence, selective excitation, infra-red spectrum, and etc. More detailed items of the thesis work were list as below.1. Yb³⁺/Er³⁺ co-doped cubic Y₂O₃ nano-tubes, nano-particles and nano-flakes were synthesized by using a hydrothermal method. All the three nanostructures showed good ability in up-conversion emitting. The dependence of their fluorescence properties on morphologies was found in the FTIR and fluorescent decay measurements. The spectral changes from nanotubes to nanoflakes indicate that the OH^- group in them plays an important role in the effect on their spectral properties. OH^- ions with high vibration更多还原