湿固相机械化学法制备蓝粉前驱体过程中的物相转变

The phase evolution during the synthesizing process of blue phosphor precursor by wet-solid mechanochemical processing

采用湿固相机械化学法制备稀土铝酸盐蓝色荧光粉前驱体 ,用XRD和DTA TG分析技术研究了湿固相球磨过程和后续煅烧过程中的物相转变。结果表明 :在球磨过程中反应原料经历了无定型化与水热结晶两个主要阶段 ,观察到了MgAl2 O4 尖晶石结构相的形成和BaMg(CO3) 2 及BaCO3的再结晶现象 ,这些晶相在 64 0℃之前仍保持稳定。在烧成过程 ,首先发生无定型Al(OH) 3的分解 ,而后是分两个阶段的BaMg(CO3) 2和BaCO3分解过程。到 90 0℃时 ,碳酸盐的分解才基本结束 ,但没有形成高温固相反应所得到的BaMgAl1 0 O1 6 晶相。扫描电镜观察和粒度分析结果表明所得前驱体为粒度 1～ 3 μm ,分散性良好的亚球形蓝色荧光粉前驱体。

In this paper, a wet solid phase mechanochemical method was used to synthesize the precursor of rare earth aluminate blue emitting phosphor. The phase evolution during milling and annealing process were examined by using XRD and DTA TG analysis technology. The results show that two phase transfer processes were taken place during milling, the first is the amorphization process. And the second is the re crystallization under a quist hydrothermal condition. The formation of crystalline MgAl 2O 4 and the re crystallization of BaMg(CO 3) 2 or BaCO 3 were observed, these crystal phase were found to be stabilized before 640℃. During the annealing process, the decomposition of Al(OH) 3 was taken place at first before 300℃, and then is the two stages decomposition process of BaMg(CO 3) 2 and BaCO 3. At 900℃, the decomposition of carbonate ended, but no crystalline BaMgAl 10 O 16 , which is the main crystal phase of rare earth aluminate phosphor formed with high temperature solid reaction, was formed. The results of SEM photograph and particle size analysis show that the synthesized precursor was favorable dispersion powder with particle size ranging from 1μm to 3μm .