水热反应时间对Ca5（PO4）3（OH）：Eu荧光粉发光性能的影响

在水热反应过程中,水热反应时间是影响纳米晶颗粒尺寸和结晶性的主要因素之一。利用水热合成法,调控水热反应时间,制备了Ca5（PO4）3（OH）：Eu纳米荧光粉。通过X射线衍射、扫描电子显微镜和荧光光谱对合成样品的结构和性能进行了表征。结果表明所合成的样品都为纯的六方相Ca5（PO4）3（OH）纳米颗粒,延长反应时间有利于Ca5（PO4）3（OH）：Eu纳米晶颗粒的长大以及结晶性提高,但对纳米颗粒的形貌影响很小。当采用345nm作为激发波长时,观察到强的蓝光宽带发射峰,可能来自于基质本征发射,而位于长波区域弱的窄线红光发射,应该属于稀土Eu3＋离子的特征发射峰,同时,对荧光发射强度随着纳米颗粒尺寸变化的原因进行了初步探讨。

Effects of Hydrothermal Reaction Time on the Fluorescence Properties of Nanosized Ca5（PO4）3（OH） ： Eu Powders

During the hydrothermal process,the reaction time is one of the main factors which has an effect on the particles size and crystalline of nanocrystals. In this work,Ca5（ PO4）3（ OH） ： Eu powders were synthesized by a hydrothermal method. X- ray powder diffraction（ XRD）,scanning electron microscopy（ SEM）,and photoluminescence spectroscopy（ PL）were utilized to characterize the structure,size and shape of the nanoparticles,which indicated hexagonal phase Ca5（ PO4）3（ OH） nanoparticles. On prolonging the hydrothermal reaction time from 2 to 16 h,the average particle sizes of these nanoparticles increased readily from 19. 6 to 63. 6 nm with improving the crystallinity,but the shape of these nanoparticles did not show apparent changes.The photoluminescence measurement revealed that the luminescent emission spectrum is composed of a strong blue broad band emission peak and the weak narrow emission peak under excitation at 345 nm. The former peak maybe arise from the intrinsic emission of Ca5（ PO4）3（ OH） matrix,while the latter one should be ascribed to the characteristic emissions of Eu3 ＋ion. In addition,the variations of the fluorescence emission intensity as the particle size have carried on the preliminary discussion.