非硅醇盐无机溶胶凝胶法合成蓝色发光材料Sr_2MgSi_2O_7:Eu^(2+),Dy^(3+)

Synthesis of Blue Long-lasting Phosphorescent Material Sr_2MgSi_2O_7:Eu^(2+),Dy^(3+) by Inorganic Sol-gel Method

以水玻璃(Na2SiO3)为硅源,柠檬酸三铵为PH值调节剂,通过离子交换,采用溶胶凝胶法低温合成Sr2MgSi2O7&Eu2+,Dy3+蓝色发光材料。采用DTA、XRD、荧光光谱等手段对材料进行分析和表征,结果表明:前驱体干凝胶煅烧到1010℃后开始有Sr2MgSi2O7相形成,到1100℃完全转变成高纯相Sr2MgSi2O7,其产物疏松,颗粒小,不需研磨或稍加研磨便得超细粉。它的激发光谱在250～450nm之间存在一个强度较高的激发带,发射峰位于467nm,余辉时间超8h。此外,对溶胶凝胶的形成机理等进行了讨论。

Blue long-lasting phosphorescent materials with high brightness, Srz MgSi20T：Eu2＋, Dy3＋, were prepared by sol-gel method using sodium silicate （Na2 SiO3） as the silicon source. Ammonium citrate tribasic as a catalyzer controlled the polymerization of sol by adjusting pH value of the system. The products were characterized by differential-thermal analysis （DTA）, X-ray diffractometry （XRD） and fluorescence spectroscopy. The results indicated that Sr2 MgSi2 07：Eu2＋ , Dya＋ begin to form when the xerogel precursor was calcined at 1010℃, and possessed pure phase with a tetragonal crystal structure when it was sintered at 1100℃ for 3 h. It is easy to grind the material into superfine powder. The material has photoluminescence with blue long afterglow luminescent behavior, and its luminescent persistence time lasts more than 8 h. The sample shows broadband excitation in the wave band of 250--450 nm and intense blue luminescence with the central wavelength at 467 nm. In addition, the formation mechanism of the colloidal silica sol and gel is discussed.