Mo-La_2O_3阴极碳化机理  

Carbonization mechanism of Mo-La_2O_3 cathode

作　　者：周文元[1] 张久兴[1] 周美玲[1] 杜玮[1] 左铁镛[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：《中国有色金属学报》2002年第6期1242-1245,共4页The Chinese Journal of Nonferrous Metals

基　　金：国家重点基础研究发展规划资助项目 (G19980 6 1316 )

摘　　要：研究了碳化温度、碳化时间、碳化时苯的压强对Mo La2 O3 阴极碳化度大小和碳化层组织的影响。结果表明 :在 172 3K ,苯的压强为 1.5× 10 -2 Pa,碳化 6min后Mo La2 O3 阴极碳化度达到 19.7%,碳化层为疏松多孔的Mo2 C组织 ,有利于阴极热电子发射。应用扫描电镜 (SEM)、X射线衍射仪 (XRD)等手段对Mo La2 O3 阴极碳化层的显微组织和微观结构、物相等进行了观察与分析。并从热力学与动力学两方面对Mo La2 O3 阴极碳化机理进行了探讨。The carbonizing process of Mo-La 2O 3 cathode are investigated and the microstructures and phases of it's carbonized layers are studied by TEM and XRD. The carbonizing temperature, carbonizing time and the pressure of benzene (C 6H 6) are the decisive factors. In the adequate benzene vapor (1.5×10 -2 Pa), Mo-La 2O 3 cathodes carbonized at 1 723 K and for 6 min can obtain maximum carbonized ratio and coarse Mo 2C particles carbonized layers, which is beneficial to the migration of activated rareearth element to the surface of the cathode during the operating. The carbonization mechanism of Mo-La 2O 3 cathode is also discussed.

关 键 词：Mo-La2O3阴极 碳化度 组织 热电子发射 碳化机理 大功率电子管 

分 类 号：TN11[电子电信—物理电子学] TN104