溶胶-凝胶法合成BaMgAl_(10)O_(17)粉末

PREPARATION OF BaMgAl_(10) O_(17) BY SOL-GEL PROCESS

以自制活性氢氧化铝为原料 ,将其与BaCO3 和Mg(OH) 2 ·4MgCO3·6H2 O共同溶解于柠檬酸中 ,采用溶胶 -凝胶法合成了BaMgAl1 0 O1 7粉末 .H+ 和NO3- 对溶胶和凝胶的形成过程有重要影响 ,减少H+ 和NO3- 的数量是形成透明溶胶和凝胶的基础 .XRD分析表明 :用此工艺制备的粉体 130 0℃煅烧 ,就可完全结晶成单相BaMgAl1 0 O1 7.不同工艺处理的干凝胶 ,其煅烧后的粉体形貌不同 ,但在经预烧和球磨后再煅烧 ,由SEM观察所得的粉体粒径皆为 1～ 5

A simple sol-gel process was employed by using citric acid as a chelating agent to synthesize fine BaMgAl 10 O 17 powder. BaCO 3, Mg(OH) 2·4MgCO 3·6H 2O and self_made active Al(OH) 3 were dissolved in citric acid to get transparent solution which was then heated at certain temperature to get transparent gel. BaMgAl 10 O 17 powder was obtained by sintering the dry gel. H + and NO 3 -are found to have a great effect on the formation of sol and gel and it is necessary to decrease the amount of H+ and NO 3 - to obtain transparent sol and gel. It take 6 days to obtain the transparent gel when the gelation temperature is 70 ℃, and 1.5 h are enough to get transparent gel when the gelation temperature was 96 ℃. BaMgAl 10 O 17 is crystallized completely when the dried gel was sintered at 1 300 ℃ according to the XRD results. Two different processes are employed to obtain the BaMgAl 10 O 17 powder: one is to sinter the dry gel at 1 300 ℃ directly, and the other is to calcine the dry gel at lower temperature. The morphology of the particle is different when the processes of obtaining the phosphor are different. Phosphor particle size sintered at 1 300 ℃ after calcining and grinding is in the range of 1～5 μm observed by SEM.