LaF3纳米片和棒束的选择性合成及表征

摘要

室温条件下,以简单的液相法,通过改变氟源NaBF4和K2SiF6,制得不同形貌的LaF3纳米晶(片及棒束).X射线衍射(XRD)结果显示所得的2种不同形貌的产物均为结晶良好的六方相LaF3.场发射扫描电子显微镜(FE-SEM)、透射电子显微镜(TEM)结果表明由NaBF4制得大量均匀、厚度约为20 am的六边形纳米片.而由K2SiF6得到平均直径约200 nm、长度约400 nm的棒束.本文详细讨论了氟源种类、反应时间、温度、反应物比例等反应参数对产物LaF2形貌的影响.提出了可能的反应机理并进一步研究了掺杂产物IaF3:Eu3+及IJaF3:Tb3+在室温下的荧光性质.%At room temperature,LaF3 nanocrystals with different morphologies(plates and bundles)have been successfully fabricated via a simple solution route by varying the fluoride source(NaBF4 and K2SiF6).X-ray powder diffraction(XRD)results indicate that all the as-prepared different morphological LaF3 products have hexagonal structure and hilgh crystallinity.Field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) results show that large-scale and uniform hexagonal nanoplates with thickness about 20 nm can be easily synthesized from NaBF4,while bundles with diameter of 200 nm and length about 400 am have been prepared from K2SiF6- Some reaction parameters(fluoride source,reaction time,temperature and molar ratio of reactants)have been systematically investigated during the process of obtaining different morphological LaF3.Furthermore,a possible reaction mechanism for the growth of LaF3 is proposed and the room temperature photoluminescent properties of LaF3:Eu3+ and LaF3:Tb3+ crystals have been measured.