ABSTRACT
Carbon nanotubes are novel materials with unique electrical and mechanical properties. Here we present our results on their structure and interactions in the adsorbed state, on their self-organization into rings, on ways to manipulate individual nanotubes, on their electrical properties and how these properties are affected by structural distortions, and, finally, on the fabrication and characteristics of nanotube-based electron devices. Specifically, atomic force microscopy (AFM) and molecular mechanics simulations are used to investigate the effects of van der Waals interactions on the atomic structure of adsorbed nanotubes. Both radial and axial structural deformations are identified and the value of the interaction energy itself is obtained from the observed deformations. We demonstrate that the strong substrate-nanotube interaction allows the AFM manipulation of both position and shape of individual nanotubes at surfaces. We then concentrate on the electrical transport properties of nanotubes. We briefly review the literature and discuss recent theoretical results concerning the effect of structural distortions of nanotubes on their electrical properties. Preliminary results regarding the effects of a magnetic field on the transport of nanotube are also reported. Finally, we demonstrate the operations of a field-effect transistor based on a single semiconducting nanotube, and a single-electron transistor using a nanotube bundle as Coulomb island.
