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Synthesis Of New-style Long Afterglow Luminescent Material And Its Properties

Posted on:2005-07-19Degree:MasterType:Thesis
Country:ChinaCandidate:W ChenFull Text:PDF
GTID:2121360122490541Subject:Materials science
Abstract/Summary:PDF Full Text Request
It is light that the world is flowery and colorized because of. The research and applications of luminescent materials have changed our lives importantly and admirably. As one of the most important state luminescent materials, the long afterglow phosphors had been researched as early as 70s of 19 century. With the development and progress of society, the requirement of these materials is boosting.In 1990s, the new long afterglow phosphors were synthesized, and were attended especially because of their better luminescence properties. At present, the research is focused more on the system of aluminate than silicate. The silicate is more stable than the aluminate. and have better adaptable, but its luminescence properties do not achieve aluminates\ There a lot of work must be done for improving the luminescence properties of silicate.The paper have researched detailedly the system of Sr2MgSi2O7:Eu2+,Dy3+. The long afterglow luminescent material of Sr2MgSi2O7 was prepared by sintering at high temperature under the deoxidization atmosphere. With arthogonality experiment method and XRD,TG-DTA, the luminescent properties and the factors of influence on them were studied, and the optimum condition of sintering was determined. The luminous intensity of phosphor-powder synthesized by this method is 32mcd/m2 after the sample was excitated 300s, and the decay time of the sample is 350min.A phosphors of Sr2MgSi2O7:Eu2+,Dy3+ was synthesized first time with sol-gel methods at the temperature lower than the tradition solid state reaction about 200℃ from Si(OC2H5)4. MgO, Sr(NO3)2, Eu2O3, Dy2O3. The transitions from sol to gel and from gel to luminescent crystal were studied with XRD TG-DTA. The testing result of luminescent properties shows that the luminescent performance of the sample synthesized with sol-gel methods was better than theone synthesized with solid state reaction. The luminous intensity of phosphor-powder synthesized by sol-gel method is 65mcd/m2 after the sample was excitated 300s. and the decay time of the sample is 380min.This paper has discussed luminescence mechanism of Sr2MgSi2O7:Eu2+,Dy3+ through analyzing the luminescence mechanism of aluminate system based on a lot of references. The luminescence action of Sr2MgSi2O7:Eu2+,Dy3+ was explained using the configuration coordinate model.
Keywords/Search Tags:long afterglow, luminescent materials, silicate, solid-state reaction, sol-gel methods
PDF Full Text Request
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