Li2O-CaO-Gd2O3-SiO2:Eu,Bi体系的结构和发光性能之间的关系

用X射线粉末衍射法研究了Li₂O-CaO-Gd₂O₃-SiO₂:Eu,Bi发光体系的物相组成随Gd₂O₃含量的变化,探讨了不同硅酸盐物种和结构对Eu³⁺和Bi³⁺发光特性的影响。结果表明,无Gd₂O₃组分时发光体是β-CaSiO₄多晶体,当Gd₂O₃/SiO₂比超过2.5%时,Ca₂Gd₈(SiO₄)₆O₂和LiGd₉(SiO₄)₆O₂物相逐渐增加,当其成为主要物相时,EU³⁺发光呈数倍增强,这2种含钆物相的结构既利于EU³⁺的红光发射又利于敏化剂向激活剂传输能量,所形成的固熔体是优良的发光基质材料。

Relationship Between Luminescent Properties and Structures of Li_2O-CaO-Gd_2O_3-SiO_2 :Eu,Bi System

The variations of phase components depending on the concentrations of Gd₂O₃ in the system of Li₂O-CaO-Gd₂O₃-SiO₂:Eu,Bi were studied by powder X-ray diffraction.It was investigated that the structures and species of silicates affect the luminescent properties of Eu(Ⅱ) ion and Bi(Ⅲ) ion.If Gd concentration is small, the product is β-Ca₂SiO₄.The phases Ca₂Cd₈(SiO₄)₆O₂ and LiCd₉(SiO₄)₆O₂ appear and their contents increase with Gd₂/O₃ being 0.25 when the ratio Gd₂O₃/SiO₂ is more than 2.5 wt% .The luminescence intensity of Eu³⁺ ion in the sample is five times that of Eu³⁺ ion in the sample with Gd₂O₃/SiO₂ being 0.2.The structures of the two phases containing Gd favor both red emission of Eu³⁺ ion and energy transfer from sensitizer to activator.The solid solution formed by the two compounds is a better host material than single LiCd₉(SiO₄)₆O₂ phase.