摘要
采用放电等离子烧结–光学悬浮区域熔炼–高温活性金属Ti还原相结合的制备方法成功获得了[Ca24Al28O64]4+:4e-(C12A7:e-)单晶体。测试了C12A7:e-的电子浓度,在800～1 100℃温度范围内测试了C12A7:e-单晶体自由生长面的热电子发射性能。结果表明:以活性金属Ti作为还原剂,在1 100℃还原30 h后,获得了接近理论电子浓度最大值(2.1×1021 cm-3)的C12A7:e-单晶,室温下的电导率达到1.96×103S/cm。在1 100℃,电压为3.5 kV时,发射电流密度达到最大值1.25 A/cm^2,平均有效逸出功为1.81 eV,表现出良好的热发射性能。
A single crystal of [Ca24Al28O64]4+:4e-(C12A7:e-) was prepared via a spark plasma sintering(SPS)–floating zone(Fz)–Ti metal reduction method. The electron concentration of C12A7:e-was measured and its thermionic emission properties of free growth surface at 800-1 100 ℃ were also investigated. The results show that after the reduction treatment with Ti metal at 1 100 ℃ for 30 h, a C12A7:e-single crystal with a theoretical maximum electron concentration(2.1×1021 cm-3) is obtained, and the electrical conductivity at room temperature is 1.96×103 S/cm. The emission current density reaches a maximum value of 1.25 A/cm2 at 1 100 ℃ with a voltage of 3.5 kV. The average effective work function is 1.81 e V, showing a good thermionic emission performance.
作者
赵吉平
张忻
刘洪亮
肖怡新
江浩
张久兴
ZHAO Jiping;ZHANG Xin;LIU Hongliang;XIAO Yixin;JIANG Hao;ZHANG Jiuxing(Key Laboratory of Advanced Functional Materials, Ministry of Education, College of Materials Science and Engineering,Beijing University of Technology, Beijing 100124, China;School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009, China)
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2019年第1期33-38,共6页
Journal of The Chinese Ceramic Society
基金
国家自然科学基金项目(51371010)
关键词
七铝酸十二钙化合物
单晶体
电输运
热发射
mayenite compound
single crystal
electrical transport
thermionic emission
