Functionalized carbon nanotubes and device applications

Carbon nanotubes, in which the two-dimensional hexagonal lattice of graphene is transformed into a quasi-one-dimensional lattice by conserving the local bond arrangement, provide several structural parameters for engineering novel physical properties suitable for ultimate miniaturization. Recent interest in nanoscience and nanotechnology has driven a tremendous research activity in carbon nanotubes, which has dealt with a variety of problems and produced a number of new results. Most of the effort has gone into revealing various physical properties of nanotubes and functionalizing them in different ways. This paper covers a narrow region in this enormous research field and reviews only a limited number of recent studies which fit within its scope. First, we examine selected physical properties of bare carbon nanotubes, and then study how the mechanical and electronic properties of different tubes can be modified by radial strain, structural defects and adsorption of foreign atoms and molecules. Magnetization of carbon nanotubes by foreign atom adsorption has been of particular interest. Finally, we discuss specific device models as well as fabricated devices which exploit various properties of carbon nanotubes.