摘要
采用稀土金属Ce元素固溶掺杂改性LaB6以降低其电子逸出功的策略,先通过熔盐法制备出La1-x Cex B6(x=0.2,0.4,0.6,0.8)固溶体纳米粉体,后经热压烧结得到La1-x Cex B6阴极材料。利用XRD、SEM等技术表征La1-x Cex B6阴极材料的组成结构,并研究了Ce元素固溶掺杂对LaB6阴极材料电子逸出功的影响。结果表明,所制备的La1-x Cex B6阴极材料为单相固溶体,致密度高,相对密度介于98.49%-98.98%之间。相对于未掺杂LaB6阴极材料,La1-x Cex B6阴极材料的电子逸出功更低,且随着Ce掺杂含量的增加电子逸出功先减小后增大,整体介于1.85-2.54 eV之间,其中La0.6Ce0.4B6阴极材料的电子逸出功最低,仅为1.85 eV。固溶掺杂Ce是降低LaB6阴极材料电子逸出功的有效途径。
Rare earth Ce was selected as doping element to reduce work function of LaB6. Firstly, La1-x Cex B6(x=0.2, 0.4, 0.6, 0.8) solid solution nanopowders were prepared by a molten salt route, and then they were used as raw materials to fabricate La1-x Cex B6 cathode materials by hot pressing sintering. XRD and SEM technology were used to investigate microstructures of La1-x Cex B6 cathode materials.The effect of Ce doping on work function of LaB6 cathode material was studied. The results show that the La1-x Cex B6 cathode materials fabricated by hot pressing sintering of La1-x Cex B6 nanopowders are single phase solid solution, and their relative densities range from 98.49%-98.98%. The work functions of La1-x Cex B6 cathode materials are between 1.85 and 2.54 eV, all lower than that of LaB6 without Ce doping. Besides, work function of La1-x Cex B6 cathode materials decreases at first and then increases with the increase of the Ce content.La0.6 Ce0.4 B6 cathode material has the lowest work function of 1.85 eV. Solid solution doping of rare earth Ce is an effective way to reduce work function of LaB6 cathode material.
作者
余艺平
王松
李伟
Yu Yiping;Wang Song;Li Wei(Science and Technology on Advanced Ceramic Fibers and Composite Laboratory,College of Aerospace Science and Engineering,National University of Defense Technology,Changsha 410073,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2021年第6期2201-2207,共7页
Rare Metal Materials and Engineering
基金
国家自然科学基金(51902342)。
关键词
六硼化镧
固溶掺杂
电子逸出功
lanthanum hexaboride
solid solution doping
work function
