Formation and electronic properties of double-walled boron nitride nanotubes

The electronic and structural properties of double-walled boron nitride (BN) nanotubes are studied using the first principle pseudopotential density functional method. It is shown that zigzag-type tubes have a larger formation energy for the double-walled configuration than the armchair-type structure, and that interwall stacking plays a significant role for intertube interactions and in the formation of multiwall BN nanotubes. The fundamental energy gap of double-walled BN nanotubes was found to be smaller than that of single-walled tubes mostly due to band shift. It is shown that the electronic properties of double-walled BN tubes exhibit a slight but noticeable difference for the zigzag and armchair type tubes studied.