Size effect of half-metallic properties of BN/C hybrid nanoribbons

Based on the first-principle calculations performed by Vienna Ab initio simulation package (VASP), we report the size limitation of half-metallic properties in hybrid zigzag BCN nanoribbons. Both boron–carbon (B–C) and nitrogen–carbon (N–C) interfacial hybrid zigzag BCN nanoribbons are considered. We find that all hybrid systems establish antiferromagnetic ground states. Moreover their electronic properties are mainly determined by the carbon rather than boron nitride segments. Transitions between semiconductor, half-metal and metal can be realized in both systems as the width of the carbon segment increases. However, the half-metallic property can only exist in the systems for which the zigzag carbon chain is less than 6 and 9 for B–C and N–C interfacial systems, respectively. As long as the carbon segment is wider than the above sizes, the systems behave as metals. This effect derives from the electron or hole doping of carbon on the BN segment.