柠檬酸溶胶-凝胶法合成BaAl12-xO19∶Mnx荧光粉

以AlCl₃·6H₂O，BaCO₃和MnCO₃为原料，分别溶于去离子水和柠檬酸中，采用溶胶-凝胶法合成了BaAl_12-xO₁₉∶Mn_x荧光粉。IR分析表明，干凝胶具有柠檬酸盐结构。XRD分析表明，1200℃煅烧，粉末中的主要成分为BaAl₂O₄，1400℃煅烧，粉末为BaAl_12-xO₁₉∶Mn_x和BaAl₂O₄的混合物，此时仍残余部分BaAl₂O₄，1500℃煅烧能合成单相BaAl_12-xO₁₉∶Mn_x，相对于传统的高温固相合成法降低100～300℃。SEM分析表明，晶粒较小且具有片状结构。碱土金属离子Mg²⁺,Ca²⁺和Sr²⁺的掺杂对BaAl_12-xO₁₉∶Mn_x荧光粉的发光性能有一定的影响。

Synthesis of BaAl12-xO19:Mnx phosphors by citric acid sol-gel process

A simple sol-gel process was employed by using citric acid as a chelating agent to synthesize BaAl_12-xO₁₉∶Mn_x phosphors. AlCl₃·6H₂O, BaCO₃ and MnCO₃ were dissolved in deionized water and citric acid separately to get a transparent solution which was then heated at a certain temperature to get a wet gel. BaAl_12-xO₁₉∶Mn_x powder was obtained by calcining the xetrogel. By means of the infrared spectroscopy(IR), differential thermal analysis(DTA), X-ray diffraction(XRD) and the scanning electron microscope(SEM) techniques, the phase composition of the precursor and its calcinations at different temperatures were investigated. The results showed that the structure of the precursor was a citrate and BaAl_12-xO₁₉∶Mn_x could be synthesized if the calcining temperature was up to 1500℃ and the composition was the mix of BaAl₂O₄ and BaAl_12-xO₁₉∶Mn_x if the calcining temperature was 1400℃. The main component was BaAl₂O₄ when the precursor was calcined at 1200℃. The morphology of the powder was sheet and the particle size was about a few micrometers. The Mg^2+_, Ca²⁺ and Sr²⁺ doped will influence the luminous property of BaAl_12-xO₁₉∶Mn_x phosphors.