( 北京工业大学 材料科学与工程学院,
新型功能材料教育部重点实验室, 北京 100022)
摘 要: 采用溶胶-凝胶(Sol-Gel)法成功制备了(La, Y)2O3-Mo超细粉末,利用XRD、 TEM对还原后粉末相结构、 形貌、 粒度等进行了分析。结果表明: 900℃二次还原后, 钼以单质形式存在,稀土以氧化物形式存在。 TEM观察表明,还原后稀土钼粉末粒径在70nm左右,粒度分析表明粉末D(n, 50)=80nm。 红外光谱(FT-IR)分析表明, 镧和钇通过氧与钼键合,削弱Mo=O键, 使稀土钼复合氧化物可还原性增强。能谱分析显示烧结体中稀土元素分布均匀。
关键字: 稀土氧化物; 钼; 溶胶-凝胶; 次级发射阴极
Sol-Gel method
( Key Laboratory of Advanced Functional Materials, Ministry of Education,School of Materials Science and Engineering, Beijing University of Technology,Beijing 100022, China)
Abstract: The La, Y-Mo composite oxide powder was successfully prepared by the Sol-Gel method. The technique terms are as follows: the pH value of the precursor solution is 1; the decomposition temperature is 550℃. The reduction temperature of the first step is 500℃ and that of the second is 900℃. The composition, microgram and granularity of the powder are studied by XRD and SEM experimental methods. The results show that the molybdenum appears after the second reduction at 900℃ and the rare earth oxide is present in the powder. The results of TEM show that the granularity of the RE-Mo powder is about 70nm and the average granularity is 80nm from the results of granularity analysis. The results from the infrared spectrum(FT-IR) show that the bond of Mo=O is weakened due to the bond of RE—O—Mo, which leads to the increase of the reduction properties of the RE-Mo composite oxide powders. The SEM result indicates the uniform distribution of RE elements in the sintering body.
Key words: rare earth oxides; molybdenum; Sol-Gel; second emission cathode