Ion irradiation effects on the structural deformation of multi-walled carbon nanotubes

Summary form only given. Doped nanotube has a potential step of a few eV at the junction responsible for the nonlinear conductivity so that the nano diode can be manufactured. In order to dope the N or P elements into nanotubes, it is necessary to open the end of the tubes. Here the ion irradiation method to open the end of the tubes was introduced. Experiments were carried out with various ion energies and fluxes of the irradiated ions to the multi-walled carbon nanotubes (MWNTs). The irradiated ion energy and flux can be controlled by the sheath potential and the ion plasma density near the tubes respectively. Emissive probe with the inflection point in the limit of zero emitting current method was applied to measure the sheath potentials and Langmuir probe was to measure the plasma densities near the tubes. MWNTs were grown in PECVD (Plasma Enhanced Chemical Vapor Deposition) reactor and the ion irradiation was carried out in the inductively coupled N/sub 2/ plasma. The morphology of irradiated MWNTs was studied by SEM and TEM images. It was observed that the catalyst was removed and the length of MWNTs linearly decreases with the incident ion energy and ion flux. The preliminary results show that the length of MWNTs decreases linearly with a ratio of 3.5 nm/eV for increasing the irradiation ion energy from 100 eV to 200 eV. Above 200 eV, almost of MWNTs were eliminated with remaining the small spot. With ion energies of 25/spl sim/100 eV, the catalysts were effectively removed from the top of MWNTs. Furthermore effect of the mass and flux of irradiation metallic ions on the deformation of MWNTs is presented.