氧在镧钼阴极中的作用  

Function of Oxygen in Mo-La_2O_3 Cathode

作　　者：郝世明[1] 聂祚仁[2] 

机构地区：[1]河南科技大学理学院,河南洛阳471003 [2]北京工业大学材料科学与工程学院,北京100022

出　　处：《中国稀土学报》2006年第4期434-437,共4页Journal of the Chinese Society of Rare Earths

基　　金：教育部全国优秀博士学位论文作者专项资金资助项目(200030);国家863计划资助项目(2002AA322010);河南科技大学人才科学研究基金(05-079)资助;河南科技大学校青年科学研究基金(2006QN042)资助

摘　　要：利用脉冲激光沉积在不同真空度下制备了不同La/O的La-Mo薄膜阴极,测量其发射性能并进行了原位AES分析,讨论了氧在镧钼阴极热电子发射中的作用。过多的氧易形成稳定的氧化镧,不利于电子发射;适当比例的氧可以减缓镧的蒸发,有助于阴极的稳定工作。La-O化合物中氧空位的形成有利于阴极的电子发射,氧缺位增强了镧氧化合物的半导体性。Different atomic ratio La/O film cathodes were prepared by pulsed laser deposition under various vacuum conditions. The emission properties were measured and their surface composition was investigated with in situ AES analyses. The function of oxygen in thermoionic emission of Mo-La2O3 cathode was investigated. Excess oxygen is negative to electron emission because lanthanum is easy to become stable La2O3, but proper proportion oxygen can weaken the evaporation of lanthanum and conduce to cathodes＇ stable work. The formation of oxygen vacancies enhances semiconductor property of La-O compound and improves greatly the performance of cathodes.

关 键 词：热电子发射 阴极 氧空位 稀土 

分 类 号：TG146[一般工业技术—材料科学与工程] TG422[金属学及工艺—金属材料]