Dimensionally, morphologically, and thermally induced phase transformations in boron-nitrogen nanowires

Structural, thermal, electronic, and energetic properties of cubic boron nitride (BN) nanowires are studied using the density-functional tight-binding method. The effect of the total or partial rearrangement of the cubic structure of nanowires into the hexagonal one depending on the size, morphology, and thermal treatment of the starting wire has been revealed. As distinct from the known homogeneous carbon diamond-like nanowires, stable BN nanowires are two-phase systems whose "shell" has a hexagonal structure and "core" has a cubic structure. The changes in the electronic properties of BN nanowires induced by their structural transformations are discussed. It is shown that boron-nitrogen nanowires can exhibit both semiconducting and metallic properties.