摘要
以硝酸锆、硝酸锂、Eu(NO_3)_3·6H_2O为原料,采用微波固相烧结法合成了系列红色荧光粉Li_6Zr_2O_7:Eu~(3+)。利用XRD和荧光光度计对样品的组成和发光性能进行了表征。考察了烧结时间、烧结温度及Eu~(3+)的含量对荧光粉发光性能的影响。XRD分析结果表明,Li_6Zr_2O_7:Eu~(3+)荧光粉为纯相晶体结构。根据离子电负性标度可知,Eu~(3+)(1.433)会优先取代电负性相近Zr~(4+)的位置(1.610)。当微波烧结时间为10 min、烧结温度为500℃、Eu~(3+)在晶体中的含量为14%时(以Li_6Zr_2O_7的物质的量为基准,下同),在465 nm激发下,制备得到的Li_6Zr_2O_7:0.14Eu~(3+)荧光粉在615 nm处产生最强的红光发射,且发射光谱在615 nm的强度是激发光谱在465 nm强度的1.54倍。此时荧光粉色坐标为X=0.65,Y=0.35,具有很高的色纯度,与商用红色荧光粉(0.63,0.34)相比更接近国家标准(0.67,0.33)。
A series of red-emitting phosphors Li_6Zr_2O_7:Eu~(3+)were synthesized by microwave solid phase sintering using zirconium nitrate,lithium nitrate and Eu(NO_3)_3·6H_2O as raw materials.The composition and luminescence properties of the samples were characterized by XRD and fluorescence photometer.The effects of sintering time,sintering temperature and content of Eu~(3+)on the luminescence properties of the phosphors were investigated.The results showed that the samples had crystal phases of Li_6Zr_2O_7:Eu~(3+)According to ionic electronegativity scale,Eu~(3+)(1.433)ions gave priority to replacing the position of Zr~(4+)(1.610)ions,which had similar electronegativity.When the sintering time was 10 min,the sintering temperature was 500℃,the content of Eu~(3+)ions was 14%of molar amount of Li_6Zr_2O_7,under 465 nm excitation,the prepared phosphor Li_6Zr_2O_7:0.14Eu~(3+)generated the strongest red emission at 615 nm.Its emission spectrum at 615 nm was 1.54 times stronger than that of excitation spectrum at 465 nm.At this point,its fluorescence pink coordinate was X=0.65,Y=0.35.The phosphor Li_6Zr_2O_7:0.14Eu~(3+)had very high color purity,closer to the national standard(0.67,0.33)than the commercial red-emitting phosphor(0.63,0.34).
引文
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