材料期刊网

采用Al（NO3）3、Y（NO3）3和Ce（NO3）3为母盐,碳酸氢铵为沉淀剂,利用撞击流共沉淀法制备YAG：Ce（Y3Al5O12：Ce）球形纳米粉体。利用XRD、FT-IR、SEM和荧光分光光度计对YAG前驱体及煅烧纳米粉体进行了表征,并分析了母盐溶液的浓度、溶液的滴加速度以及煅烧方法和温度对制备YAG纳米粉体的影响。结果表明母盐溶液的浓度、滴加速度及煅烧方法和温度对煅烧粉体的组成、分散性、形貌及发光性能有显著的影响。当初始原料浓度较低（c0=0.055mol/L）时,900℃可以获得纯YAG晶相,不形成任何中间相;初始浓度c0在1.0mol/L以上时,1000℃得到的YAG荧光粉中有YAM、YAP和CeO2杂质相存在;适当的提高加料速度,可以增加粉体的结晶度;采用Na2CO3-S-K2CO3助熔剂辅助煅烧,700℃时已完全转变为YAG相,与直接煅烧法相比,YAG相的完全转变温度降低了约300℃,荧光粉的发光强度比不加熔盐明显提高了。

Ce doped yttrium aluminum garnet（YAG∶Ce） spherical nanopowder was synthesized by dropping Al（NO3）3·9H2O,Y（NO3）3·6H2O and Ce（NO3）3·6H2O solution and ammonium hydrogen carbonate solution into the impinging streams reactor simultaneously at the same rate.The precursors and the YAG∶Ce powders were characterized by XRD,FT-IR,SEM and fluorescence spectrophotometer.The factors affecting the powder characteristics,including the mother salt concentration,the dropping speeds of solutions solution,and sintering methods and temperature were analyzed and discussed.The results show that the dispersion,the composition,the morphology and luminescence intensity of the YAG phosphors are affected remarkably by these factors.The YAG powders without any interphases can be obtained at 900℃ when the mother salt concentration（c0=0.055mol/L） is relatively low;the YAG phosphors including YAM,YAP and CeO2 impurity phases were prepared at 1000℃ when the mother salt concentration（c01.0mol/L） is high.The crystallinity can be increased with the increasing feeding rate at corresponding scope.The pure YAG phase could be obtained by Na2CO3-S-K2CO3 mixture flux calcination method at 700℃.Compared with the direct calcination method,the YAG∶Ce3＋ phase transition temperature with the present method can be decreased about 300℃,and the luminescent intensity of as-prepared phosphor can be increased greatly than that prepared by direct baking method.