Electronic, structural, and thermal properties of a nanocable consisting of carbon and BN nanotubes

The band structure and thermal behavior of a coaxial C/BN nanocable (5,5)C@(17,0)BN consisting of a carbon nanotube and a boron nitride nanotube have been studied using a tight-binding approximation based on density functional theory. The system is stable up to T similar to 3500-3700 K. As the temperature increases, deformations of the BN tube begin earlier than those of the carbon tube. The near-Fermi states of the nanocable are formed by the overlapping pi-pi* bands of the carbon tube, and the outer BN nanotube (the nanocable sheath) is an insulator with a bandgap of similar to4 eV. The electronic properties of the nanocable (the metallic-type conductivity of the C tube and the insulating character of the BN tube) are retained over the entire temperature interval. (C) 2004 MAIK "Nauka/Interperiodica".