论文部分内容阅读
以不同的辅助剂为形貌控制剂,采用简单的水热法合成了八面体形、梭形体、苦瓜状和纳米微球状稀土氟化物,并对其结构和性能进行了表征。X射线衍射(XRD)和扫描电子显微镜(SEM)结果表明辅助剂不同,产物的物相和形貌也不同。在没有辅助剂的情况下,得到八面体形正交晶系YF_3;以柠檬酸和无水乙醇为辅助剂时,分别得到纳米须自组装而成的梭状体和纳米粒自组装而成的苦瓜状正交晶系YF_3;而以乙二胺四乙酸(EDTA)-2Na为辅助剂时,得到的样品为立方相NaYF_4纳米微球。对氟化物的生长机理进行了探讨,并研究了其荧光性能。荧光光谱表明:正交晶系YF_3∶Eu~(3+)的最强发射峰均位于593nm,对应Eu~(3+)的~5D_0→~7F_1的磁偶极跃迁发射,但不同形貌对应的发射峰强度不一样。而立方相NaYF_4的发射光谱图包含了Eu~(3+)从激发态~5D_(0-2)到基态~7F_J的发射峰。
With different auxiliaries as the morphology control agent, octahedron, spindle, bitter gourd and nanospheroid rare earth fluoride were synthesized by simple hydrothermal method. Their structures and properties were also characterized. X-ray diffraction (XRD) and scanning electron microscopy (SEM) results show that the different adjuvants, the product phase and morphology are also different. In the absence of an adjuvant, octahedral orthorhombic YF_3 was obtained. When citric acid and ethanol were used as adjuvants, self-assembled nanostructures and nanostructures were obtained. Bitter melon-like crystal system YF_3; and ethylenediaminetetraacetic acid (EDTA) -2Na as adjuvant, the obtained sample is cubic phase NaYF_4 nanospheres. The growth mechanism of fluoride was discussed, and its fluorescence properties were studied. Fluorescence spectra showed that the strongest emission peaks of YF_3: Eu ~ (3+) in orthorhombic crystal were all located at 593 nm, corresponding to the magnetic dipole transition of ~ 5D_0 → ~ 7F_1 in Eu ~ (3+) The emission peak intensity is not the same. The emission spectrum of the cubic phase NaYF_4 contains Eu ~ (3+) emission peak from the excited state ~ 5D_ (0-2) to the ground state ~ 7F_J.