Different fluxes were used to synthesize long persistence phosphors, calcium sulfides activated by Eu 2+ and Tm 3+ , by convenient solid state method. The phosphor using NH 4F as a flux has good crystallini...Different fluxes were used to synthesize long persistence phosphors, calcium sulfides activated by Eu 2+ and Tm 3+ , by convenient solid state method. The phosphor using NH 4F as a flux has good crystallinity and large particle size, its stability against water and other atmospheric components is enhanced, and its afterglow is longer and fluorescent intensity is more intense than those of the phosphor using NH 4Cl as flux. Their PL intensities varied with time in moist air were measured, no remarkable change was found for those prepared with NH 4F flux in contrast with NH 4Cl as flux. So using NH 4F as flux is a good method to enhance the stability of alkaline earth sulfides.展开更多
采用工业频率为2.45 GHz的高温微波法制备了纯基质相的CaS∶Eu2+红色发光材料,激发波段为410~580 nm,发射峰值波长为654 nm。在微波输入功率为1.0~1.1 k W的条件下,可以获得纯基质相CaS∶Eu2+发光材料;在1.2~1.3 k W功率范围,获得的样...采用工业频率为2.45 GHz的高温微波法制备了纯基质相的CaS∶Eu2+红色发光材料,激发波段为410~580 nm,发射峰值波长为654 nm。在微波输入功率为1.0~1.1 k W的条件下,可以获得纯基质相CaS∶Eu2+发光材料;在1.2~1.3 k W功率范围,获得的样品中含有Ca O杂质相,且颗粒团聚严重。其中,1.1 k W制备的CaS∶Eu2+样品相纯度最高,发光性能最优。微波功率的变化本质上揭示了固体颗粒的介电损耗因子及其加热特性的变化,体系涉及的非平衡反应机制促使了纯基质相的形成,并影响材料晶相结构、粒径、形貌和发光性能。结果显示,高温微波制备技术通过控制输入功率及其物料的介电损耗性质,能够获得纯基质相并且颗粒小、团聚少的荧光粉。展开更多
文摘Different fluxes were used to synthesize long persistence phosphors, calcium sulfides activated by Eu 2+ and Tm 3+ , by convenient solid state method. The phosphor using NH 4F as a flux has good crystallinity and large particle size, its stability against water and other atmospheric components is enhanced, and its afterglow is longer and fluorescent intensity is more intense than those of the phosphor using NH 4Cl as flux. Their PL intensities varied with time in moist air were measured, no remarkable change was found for those prepared with NH 4F flux in contrast with NH 4Cl as flux. So using NH 4F as flux is a good method to enhance the stability of alkaline earth sulfides.
文摘采用工业频率为2.45 GHz的高温微波法制备了纯基质相的CaS∶Eu2+红色发光材料,激发波段为410~580 nm,发射峰值波长为654 nm。在微波输入功率为1.0~1.1 k W的条件下,可以获得纯基质相CaS∶Eu2+发光材料;在1.2~1.3 k W功率范围,获得的样品中含有Ca O杂质相,且颗粒团聚严重。其中,1.1 k W制备的CaS∶Eu2+样品相纯度最高,发光性能最优。微波功率的变化本质上揭示了固体颗粒的介电损耗因子及其加热特性的变化,体系涉及的非平衡反应机制促使了纯基质相的形成,并影响材料晶相结构、粒径、形貌和发光性能。结果显示,高温微波制备技术通过控制输入功率及其物料的介电损耗性质,能够获得纯基质相并且颗粒小、团聚少的荧光粉。
