IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Nanotubes: Science and Applications Topical Conference Tuesday Sessions
       Session NT-TuP

Paper NT-TuP1
Field Emission Microscopy Observation on Single-Walled Carbon Nanotubes with Atomic Resolution

Tuesday, October 30, 2001, 5:30 pm, Room 134/135

Session: Poster Session
Presenter: G.M. Zhang, Peking University, China
Authors: Z.X. Zhang, Peking University, China
G.M. Zhang, Peking University, China
M. Du, Peking University, China
X.X. Jin, Peking University, China
S.M. Hou, Peking University, China
Z.J. Shi, Peking University, China
Z.N. Gu, Peking University, China
W.M. Liu, Peking University, China
X.Y. Zhao, Peking University, China
Z.Q. Xue, Peking University, China
Correspondent: Click to Email
We assembled single-walled carbon nanotubes (SWCNs) onto tungsten carbide thin film on a tungsten tip surface, which was formed due to the segregation of carbon element in polycrystalline tungsten. Then by using Field-Emission Microscope (FEM) and quadrupole mass spectrometry, we respectively observed the field emission from the SWCNs and analyzed the components of the residual gas with the sample receiving heat treatment. The pattern of FEM image underwent obvious change as the heating temperature varied. The heat treatment at approximately 1000¡æ was found to result in the appearance of an FEM image with atomic resolution of an open-ended SWCN. The quadrupole mass spectrometry analysis showed the existence of carbon and oxygen atoms, which are believed to be released under high temperature from the spaces among the grains inside the polycrystalline tungsten. We think that these carbon and oxygen atoms imposed decoration upon the tube ends. Oxygen atoms reacted with amorphous carbon on the ends of the carbon nanotubes and generated CO and CO@sub 2@, which than escaped into vacuum. Carbon atoms might fill the defects so that relatively perfect structures resulted. We further believe that this kind of decoration led to the protrusion of an individual SWCN, which made the atomic resolution of FEM image possible.