La_2O_3-Mo热发射材料的研究  

The Study on the Thermionic Emission of La-Mo Materials

作　　者：刘燕琴[1] 刘伟[1] 崔颖[1] 张久兴[1] 王金淑[1] 周美玲[1] 

机构地区：[1]北京工业大学新型功能材料教育部重点实验室,北京100022

出　　处：《稀有金属材料与工程》2005年第3期467-470,共4页Rare Metal Materials and Engineering

基　　金：国家重点基础研究发展规划基金(973)资助项目(G19980613132);霍英东青年教师基金资助计划(81040)

摘　　要：采用溶胶凝胶(Sol-Gel)和两步氢还原及烧结法成功制备了(2%～5%),质量分数,下同)La2O3-Mo阴极粉末和烧结体,借助于XRD,SEM等手段对材料成分及微观结构进行分析.结果显示在粉末和烧结体中稀土元素La以氧化物形式存在,La2O3粒子大小为100 nm,弥散分布在烧结体基体中.热发射测试结果表明1 400℃时,零场发射电流达到J0=6 A/cm2.暴露大气48 h后,再经过1 350℃激活,发射性能得到全面恢复.The La2O3-MO precursor powder was prepared by the Sol-gel methods and two step reduction. The composition and micrograph of the (2%-5%wt)La2O3-MO materials were tested by the XRD, SEM etc methods. The results show that the rare elements La exist taking the form of La2O3 in the powder and sintering body. The La2O3 particles with granularity of less than 100 nm disperse uniformly in the 2 sintering body. The thermionic emission current at zero field reaches 7.96 A/cm(2) at 1 400 degrees C. After the exposure to the atmosphere the La2O3-MO thermionic emission performance can resume by re-activation at 1 350 degrees C

关 键 词：溶胶凝胶 稀土 钼 热阴极 

分 类 号：TB34[一般工业技术—材料科学与工程]