Rare Earth Strontium Aluminate Luminescent Materials, Low Temperature Combustion Synthesis

The preparation of nanometer-sized ceramic SrAl₂O₄:Eu²⁺,Dy³⁺ powders by low-temperature combustion synthesis was investigated in detail.Established the technology of low-temperature combustion synthesis,and studied on the Luminescent Properties of the powders.We gained the productions as following:1) SrAl₂O₄:Eu²⁺,Dy³⁺powders were prepared by LCS.The chief factors of the LCS process were studied.We confirmed the better technics parameters to prepare the excellent luminescent intensity of SrAl₂O₄: Eu²⁺,Dy³⁺ phosphor.The results showed that we opted for the aluminum nitrate and strontium nitrate solution as raw materials,as the ratio of AN/SN was 2:1,borate acid(0.10mol fraction) as flux,the quantity of urea for 2 times as much as theoretic quantity as reductant,A high-quality long lasting phosphor---SrAl₂O₄:Eu²⁺,Dy³⁺ was prepared by combustion systhesis at 550℃of igniting temperature in the furnace.It was found that the phosphor's best exciting peak wavelength were 365 nm corresponding emission peak wavelength 514.2nm by measuring the exciting spectra and the emitting spectra.The phosphor luminescent intensity is strongest under this exciting condition.2) Low temperature combustion synthesis were used to prepare the phosphor,luminescent performance were studied then.The results showed that we could get the best luminescent performance when the ratio of AN/SN was 2:1.Eu²⁺ acted as luminescence center.The critical doping concentration of Eu²⁺ at the mol fraction was 10at%,while the critical distance was 14.9(?).The doping of Dy³⁺ could improve the luminescent performance of the SrAl₂O₄:Eu²⁺,Dy³⁺ phosphor.Dy³⁺ had the ability to make a suitable trap that make it more easy to excite the SrAl₂O₄:Eu²⁺,Dy³⁺ phosphor.It acted as assistant activation medicament.3) SrAl₂O₄:Eu²⁺,Dy³⁺powders were prepared by LCS,and the Stoke s displacement were calculated.We analyzed the exciting spectra and emitting spectra of the phosphors.The results are as following.The base can affect the luminescent performance.It acted as an energy transfer.When under the best synthesis condition,the Stokes displacement got the max.