Half metallicity and electronic structures in armchair BCN-hybrid nanoribbons.

We study magnetism and electronic structures of armchair BCN-hybrid nanoribbons from density functional theory. Different from armchair graphene nanoribbons, armchair BCN-hybrid nanoribbons are found to present magnetism along the edges of the nanoribbons if B and N atoms are unpaired in the nanoribbons. Intriguing spin-polarized bands, including magnetic semiconductors, half metals, and magnetic metals, are obtained in the armchair nanoribbons with both the edges composed of C and N atoms. The spin polarization in these armchair nanoribbons is ascribed to the appearance of the unsaturated electronic states in the systems. The magnetic metallicity can be tuned further to half metallicity by adsorbing O atoms at appropriate positions in the ribbons. The electronic structures of the nanoribbons without spin polarization are also analyzed. Our studies provide understanding of the magnetism mechanisms and the electronic properties and most importantly, how to achieve half metallicity in low-dimensional BCN-hybrid systems.