Magnetism of single-walled silicon carbide nanotubes doped by boron, nitrogen and oxygen

We calculated, using spin polarized density functional theory, the electronic properties of zigzag (10,0) and armchair (6,6) semiconductor silicon carbide nanotubes (SiCNTs) doped once at the time with boron, nitrogen, and oxygen. We have looked at the two possible scenarios where the guest atom X (B, N, O), replaces the silicon X-Si, or the carbon atom X-C, in the unit cell. We found that in the case of one atom B @ SiCNT replacing a carbon atom position annotated by B-C exhibits a magnetic moment of 1 mu(B)/cell in both zigzag and armchair nanotubes. Also, B replacing Si, (B-Si), induce a magnetic moment of 0.46 mu(B)/cell in the zigzag (10,0) but no magnetic moment in armchair (6,6). For N substitution; (N-C) and (N-Si) each case induce a magnetic moment of 1 mu(B)/cell in armchair (6,6), while N-Si give rise to 0.75 mu(B)/cell in zigzag (10,0) and no magnetic moment for N-C. In contrast the case of O-C and O-Si did not produce any net magnetic moment in both zigzag and armchair geometries. (C) 2012 Elsevier B.V. All rights reserved.