沉淀剂对水热合成Sr_2CeO_4形貌及发光性质的影响  

Effect of Precipitant on Morphology and Luminescent Properties of Sr_2CeO_4 Synthesized by Hydrothermal Method

作　　者：翟永清[1] 胡志春[1] 马健[1] 李瑞芳[1] 郑强[1] 

机构地区：[1]河北大学化学与环境科学学院,保定071002

出　　处：《人工晶体学报》2013年第10期2013-2018,共6页Journal of Synthetic Crystals

基　　金：国家自然科学基金(20675023)

摘　　要：分别以（NH4）2CO3、Na2CO3为沉淀剂，采用水热法合成了Sr2CeO4蓝白光荧光粉。利用热重-差热、红外光谱及x射线衍射分析了不同沉淀剂所得前驱体的热分解过程及目标产物的形成过程；利用扫描电镜、荧光分光光度计分别对荧光粉的微观形貌、发光特性进行了分析表征。结果表明：以（NH4）2CO3、Na2CO3为沉淀剂所得前驱体晶相组成相同，均由Ce2（CO3）2O·H2O、CeCO3OH及SrCO3三相组成，经1000℃下焙烧2h均得到正交晶相的Sr2CeO4。以（NH4）2CO3为沉淀剂所得样品呈类球形，分散性较好；以Na2CO3为沉淀剂所得样品呈不规则形状，团聚现象严重。所得Sr2CeO4的激发光谱均是位于200～400nm之间的一个宽带双峰结构，发射光谱均是位于400-600Bin之间的一个宽带，最大发射峰位于466nm左右，归属于Ce4＋的f→t1g。跃迁，呈蓝白光发射。在最大激发波长下，以（NH4）2CO3为沉淀剂所得样品的发光强度相对较大。Blue-white emitting Sr2CeO4 phosphors were synthesized by hydrothermal method using （NH4 ）2CO3 and Na2CO3 as precipitant, respectively. The thermal decomposition behavior of precipitation precursors obtained using the different precipitants （（NH4） 2CO3 and Na2CO3 ） and the formation process of target product were analyzed by TG-DTA, FT-IR and XRD. The morphology and luminescent properties of phosphors were characterized by SEM and fluorescence spectrophotometer. The results showed that the precursors obtained using different precipitant have same crystal phases comPositions, which consist of Ce2 （CO3 ）2O . H2O, CeCO3OH and SrCO3, Sr2CeO4 crystallites with orthorhombic phase can be obtained after the precursors were calcined at 1000℃ for 2 h. Sr2CeO4 particles obtained using （NH4 ）2CO3 as the precipitant showed spherical-like shape and better dispersion, while those obtained using Na2CO3 as the precipitant show irregular shape and serious aggregation. The excitation spectrum of as-synthesized Sr2 CeO4 crystallite is a wide band with double peaks in the range of 200-400 nm. The emission spectrum is a broad band too, which is located in the range of 400-600 nm with the main peak at 466 nm, and it is ascribed to the f→t1g transition of Ce4＋, resulting in a blue-white emission. The luminescent intensity of the sample using （NH4 ）2CO3 as the precipitant is relatively strong under the main excitation wavelength.

关 键 词：SR2CEO4 沉淀剂 水热合成 形貌 发光 

分 类 号：O614.33[理学—无机化学]