返回
Self-regenerative field emission source
DOI:10.1063/1.2126152.png)
摘要
En 中文
A self-regenerative field emission source was demonstrated. The emission source (cathode) consisted of carbon nanofibers (CNFs) grown on the tip of conical carbon protrusions on a graphite plate. CNFs were similar to 25 nm in diameter, 0.3-2.5 mu m in length and similar to 1x10(6) mm(-2) in site density. Initial emission characteristics showed a threshold field of 3.05 V/mu m with a current density of 1 mu A/cm(2) and a field enhancement factor of 2860 from the Fowler-Nordheim plot assuming the work function of 4.6 eV for graphite. A lifetime test carried out for more than 40 h at a constant applied electric field of 10 V/mu m in 10(-4) Pa region disclosed a stable emission with a current density of 1.7-3.0x10(-4) A/cm(2) after a slight initial decrease in the emission current. Detailed morphological observations revealed that a thick layer of newly grown carbon fibers was formed on the cathode surface after the lifetime test which could be responsible for the observed stable and long-sustained emission under a nonultrahigh vacuum condition. Their growth was attributed to the surface diffusion of carbon atoms generated by sputtering of the carbon cathode with ionized residual gas molecules during the field emission process. Thus, the CNF-tipped carbon emitter was believed to be promising as a practical field electron emission source used under low vacuum. (C) 2005 American Institute of Physics.
Keyword:
CARBON NANOTUBES
ELECTRON-EMISSION
NANOFIBERS
EMITTERS
GROWTH
AI总结
对已上传原文的论文进行重点信息的提取,主要内容包括:简要概述、研究摘要、背景介绍、关键亮点、图文解析、展望与总结。
期刊
IF:
3.6
论文数:
10.4W
被引数:
17.8W
机构
暂无机构信息

