Magnetism in armchair BC₂ N nanoribbons

We show by first-principles calculations that H-terminated armchair BC ₂ N nanoribbons (a -BC₂ NNRs) have exceptional electronic and magnetic properties. In particular, a -BC₂ NNRs with the B and N atoms uncoordinated can be either p - or n -doped semiconductors, and the wide ones own spontaneous magnetization. It is shown that the magnetism is induced by the localization of acceptor or donor levels from unpaired B or N atoms, and the magnetic moment increases with further increasing ribbon width. The a -BC₂ NNRs with B and N atoms coordinated have band gaps decreasing with increasing ribbon width.