LaF_3∶Eu^(3+)纳米粒子的水热法制备及发光性质研究

Hydrothermal Preparation and Luminescence of LaF_3∶Eu^(3+) Nanoparticles

用水热法制备了LaF3及Eu3+掺杂的LaF3纳米粒子,通过X射线粉末衍射(XRD)、透射电子显微镜(TEM)和荧光光谱(FS)对样品进行了表征。结果表明:所得的纳米粒子粒度均匀、结晶完好,呈规则的六边形形状;研究了反应温度和时间对LaF3纳米粒子形成的影响,初步探讨了纳米粒子的生长机制。研究了掺杂Eu3+后的发光性质,发现纳米粒子经高温煅烧后,荧光强度有明显下降,适宜的煅烧条件为600℃/6 h,Eu3+的掺杂量在5%(摩尔分数)时,纳米粒子的荧光强度最强,更高的掺杂浓度将导致荧光猝灭。

Pure and Eu^3＋-doped LaF3 nanoparticles were prepared by a hydrothermal process at a low temperature and characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM） and fluorescence spectra. Well-dispersed nanoparticles with an average size of 30 nm and a hexagonal shape were synthesized. The effects of temperature and reaction time on the preparation of nanoparticles were investigated, and the growth mechanism of nanoparticles was briefly discussed. The centration, the calcination effects of Eu^3＋-doped concentration,the calcination time and temperature were also investigated. An optimal Eu^3＋-doped concentration of 5 % （mole fraction） is found. Calcination of the nanoparticles at high temperature and prolonged time greatly reduce the fluorescence intensity. The sample calcinated at 600 ℃ for 6 h emits the strongest fluorescence.