Bonding and structure in B_xN_y nanotubes (x, y = 1,2)

Although it has been widely established that the electronic properties of carbon nanotubes are strongly linked to their chirality, boron nitride nanotubes, which are structurally similar, are uniformly insulating irrespective of their chiral index. The production of boron nitride nanotubes with metallic or semiconducting behaviour will therefore require more specific intervention, by chemically altering the stoichiometry or distribution of the boron and nitrogen atoms with respect to one another. Some of these chemical and structural combinations will be stable, while others will not. In the present study we use first principles computer simulations to investigate the bonding and structure of B_xN_y nanotubes, for the case of x, y = 1,2. The results indicate that B₂N nanotubes represent viable candidates for synthesis efforts, although the resultant structures are decorated with defective sites produced by the breaking of unstable N-N bonds.