摘要
利用范氏力将单壁碳纳米管样品组装到钨针尖上 ,用FEM/FIM对同一碳纳米管样品用热处理方法和场脱附方法进行了研究。场离子显微镜是具有原子级分辨能力的尖端表面分析工具 ,由场离子像推测这次组装的样品是由三根单壁碳纳米管突起组成的碳纳米管束。清洁碳纳米管束样品的场发射像和场离子像有极好的对应关系。场脱附后的碳纳米管束的场发射特性较好地符合Fowler Nordheim场发射模型。通过比较碳纳米管束吸附态和热处理后以及场脱附后的Fowler Nordheim曲线的斜率变化 ,得出碳纳米管束样品逸出功的变化 。
Single wall carbon nanotubes (SWCNTs) were assembled onto tungsten tips by Van der Waals force. The influence of heat treatment and field desorption on these SWCNTs was studied by field emission microscopy (FEM) and field ion microscopy (FIM) respectively. The obtained FIM images are believed to result from a thin bundle consisting of three individual SWCNTs. FEM images from clean state of the same sample were in very good agreement with FIM images. After field desorption, field emission from SWCNTs follows the Fowler-Nordheim equation more strictly. The change in the slope of Fowler-Nordheim plots reveals that the heat treatment and field desorption result in changes of work function of SWCNTs. The change in both work function and FEM/FIM images show that a combination of heat treatment and field desorption is a feasible way to obtain clean carbon nanotubes with better field emission properties.
出处
《真空科学与技术》
EI
CSCD
北大核心
2003年第1期1-4,共4页
Vacuum Science and Technology
基金
国家自然科学基金 (No 60 2 3 10 10
90 2 0 60 48
60 12 810 1
60 1710 2 5 )
国家重点基础研究资助项目 (No 2 0 0 1CB610 5 0 3 )
教育部博士点基金 (No 2 0 0 2 0 0 0 10 0 3 )
