DEFECTS IN CARBON NANOSTRUCTURES

Previous high-resolution electron microscopy (HREM) observations of th e carbon nanotubes have led to a ''Russian doll'' structural model tha t is based on hollow concentric cylinders capped at both ends. The str uctures of the carbon nanotubes and particles were characterized here by bulk physical and chemical property measurements. The individual na nostructure is as compressible as graphite in the c axis, and such nan ostructures can be intercalated with potassium and rubidium, leading t o a saturation composition of ''MC(8).'' These results are counter to expectations that are based on a Russian doll structure. HREM after in tercalation with potassium and deintercalation indicates that individu al nanoparticles are a ''paper-mache'' of smaller graphite layers. Dir ect current magnetization and electron spin resonance measurements ind icate that the electronic properties of the nanostructures are distinc tly different from those of graphite. Although the nanostructures have distinct morphologies and electronic properties, they are highly defe ctive and have a local structure similar to turbostratic graphite.