白光LED用新型红色荧光粉Li2SrSiO4:Eu3+的合成及性质

以金属硝酸盐为原料,正硅酸乙酯为硅源,采用凝胶-燃烧法合成了新型红色荧光粉Li2SrSi04:Eu3+,用红外分光光度计、X射线粉末衍射仪、荧光分光光度计等手段研究了该荧光粉的形成过程、结构及发光性能.结果表明:凝胶燃烧所得前驱物在700℃焙烧3h即得目标产物Li2SrSi04:Eu3+,其晶体结构属六方晶系,空间群为...     

电荷补偿剂对Sr2MgSi2O7：Eu3＋红色发光粉结构和性能的影响

采用微波辅助凝胶燃烧法制备Sr2MgSi2O7：Eu3＋,R＋（R=Li,Na,K）系列红色发光粉,通过X射线粉末衍射、荧光分光光度计等分析表征荧光粉的结构以及发光性能。结果表明：Sr2MgSi2O7：Eu3＋,R＋（R=Li,Na,K）系列红色发光粉的晶体结构与Sr2MgSi2O7的相同,属四方晶系;加入电荷补偿剂L...     

Properties of red-emitting phosphors Sr2MgSi2O7:Eu3+ prepared by gel-combustion method assisted by microwave

Novel red-emitting phosphors Sr2MgSi2O7:Eu3+ were prepared by gel-combustion method assisted by microwave. The phase struc-ture and luminescent properties of as-synthesized phosphors were investigated by XRD and fluorescence spectrophotometer, respectively. The results showed that the as-synthesized sample was Sr2MgSi2O7 with tetragonal crystal structure. The excitation spectrum of Sr2MgSi2O7:Eu3+ was composed of two major parts: one was the broad band between 200 and 350 nm, which belonged to the charge transfer of Eu3+-O2-; the other consisted of a series of sharp lines between 350 and 450 nm, ascribed to the f-f transition of Eu3+. The emission spec-trum consisted of two emission peaks at 593 and 616 nm, which was attributed to 5D0→7F1 and 5D0→7F2 of Eu3+, respectively. The concen-tration of Eu3+ (x) had great effect on the emission intensity of Sr2-xMgSi2O7:Eu3+x. When x varied in the range of 0.04-0.18, the intensity of emission peaks at 593 and 616 nm increased gradually with the concentration of Eu3+ increasing. It was interesting that no concentration quenching occurred. Moreover, the luminescent intensity could be greatly enhanced with incorporation of charge compensator Li+ ions.     

Sr2FeMoO6的微波合成及对酸性黑10B的降解性能研究

以MnO2为微波吸收剂,SrCO3、Fe2O3、MoO3为原料,采用微波烧结法合成了双钙钛矿型复合氧化物Sr2FeMoO6。通过X射线衍射仪对样品的物相结构进行了分析表征,采用标准四引线法测量了样品在零场下的电输运性质,采用紫外可见分光光度计测试了样品降解酸性黑10B的活性。结果表明:Sr2FeMoO6为四方晶系结构,空间群为I4/mmm,晶胞参数为:a=0.558 7nm,c=0.789 4nm,晶胞体积V=0.246 4nm3;在80～300K温度范围内,呈现典型的半导体性质。样品Sr2FeMoO6对酸性黑10B有很高的降解活性,在适宜条件下,脱色率可达98%左右。同时对脱色机理进行了探讨。