STM imaging of carbon nanotube point defects

In this work the STM investigation of nanotube point defects created by ion irradiation (e.g. vacancies) is presented. The defects appeared as hillock-like features on the STM images. These defects were compared with similar features observed on the STM images of as-grown coiled carbon nanotubes. In this case the observed hillock-like features were attributed to the non-hexagonal carbon rings, which are responsible for the growth of bent and coiled nanotube structures. For irradiation, multi-walled carbon nanotubes produced by the arc-discharge method were dispersed on highly oriented pyrolitic graphite (HOPG) surface and irradiated with Ar+ ions of 30 keV, using a low dose of D = 5 x 10(11) ions/cm(2). (c) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.