Irradiation of carbon nanotubes with a focused electron beam in the electron microscope

The paper reviews in-situ electron irradiation studies of carbon nanotubes in electron microscopes. It is shown that electron irradiation at high specimen temperature can lead to a variety of structural modifications and new morphologies of nanotubes. Radiation defects such as vacancies and interstitials are created under irradiation, but the cylindrically closed graphene layers reconstruct locally and remain coherent. The generation of curvature in graphene layers with non-hexagonal rings allows us to alter the topology of nanotubes. Several examples of irradiation-induced modifications of single- and multi-wall nanotubes are shown. Conclusions about the mobility of interstitials and vacancies are drawn which are important to explain the behaviour and the properties of nanotubes with an atomic arrangement deviating from the hexagonal network of graphene.