Eu,Dy共掺杂SrAl2O4长余辉材料制备新工艺

活化Al-Sr合金粉末水解制备SrAl₂O₄长余辉材料的前驱体,并采用高温固相反应法制备出Eu,Dy共掺杂的SrAl₂O₄长余辉材料,对其微观结构和发光特性进行了研究。实验结果表明:前驱体中Al、Sr元素在微观状态下分布均匀,所制成的长余辉发光材料的发射主峰位于520nm附近,为典型的Eu²⁺离子4f5d-4f的特征发射,初始亮度达到18cd/m²,余辉时间长达46h。

New Preparation Process of Long Afterglow Phosphor Eu and Dy Co-doped SrAl2O4

The activated Al-Sr alloy powder was put immediately into boiling pure water,with liquid-solid(ratio) of 4:1.The system was kept isothermal and stirred until white hydrolysates appears.The hydrolysates contain the mixture of Sr(OH)₂·8H₂O and Al(OH)₃ in main,included a little Al(OH)₃,AlOOH,SrCO₃,and 3SrO·Al₂O₃· 6H₂O.After heat treatment at 700℃ for 1 h,the mixture of SrO and α-Al₂O₃,γ-Al₂O₃ were formed.As a precursor,the hydrolysates after heat treatment had been used to prepare long after phosphor Eu,Dy co-doped SrAl₂O₄ at 1300℃ for 1 h.The crystal structure of hydrolysates and Eu,Dy co-doped SrAl₂O₄ were analyzed by XRD.The luminescent properties of long afterglow material were studied.The(results) showed that the crystal structure of phosphor is β phase SrAl₂O₄,the emission spectra of Eu and Dy co-doped SrAl₂O₄ lied near 520 nm,resulted from the character transition of 4f5d-4f of Eu²⁺ ion.The method can improve afterglow properties dramatically.The initial luminescent intensity of long afterglow material reached 18 cd/m²,and the duration time lasted 46 h.The improved properties are related to precipitation mechanism of AlSr alloy hydrolysates.With this procedure,SrO and Al₂O₃ will disperse evenly to effectively enlarge the contact area of the components,shorten the diffusive distance.As a result the sintering temperature could be decreased,while the reaction speed and the long afterglow fluorescent properties of the materials could be improved.