Configuration-dependent electronic and magnetic properties of graphene monolayers and nanoribbons functionalized with aryl groups

Abstract

Graphene monolayers functionalized with aryl groups exhibit configuration-dependent electronic and magnetic properties. The aryl groups were adsorbed in pairs of neighboring atoms in the same sublattice A (different sublattices) of graphene monolayers, denoted as the M2AA (M2AB) configuration. The M2AA configuration behaved as a ferromagnetic semiconductor. The band gaps for the majority and minority bands were 1.1 eV and 1.2 eV, respectively. The M 2AB configuration behaved as a nonmagnetic semiconductor with a band gap of 0.8 eV. Each aryl group could induce 1 Bohr magneton (μB) into the molecule-graphene system. Armchair graphene nanoribbons (GNRs) exhibited the same configuration-dependent magnetic properties as the graphene monolayers. The net spin of the functionalized zigzag GNRs was mainly localized on the edges demonstrating an adsorption site-dependent magnetism. For the zigzag GNRs, both the M2AA and M2AB configurations possibly had a magnetic moment. Each aryl group could induce 1.5-3.5 μB into the molecule-graphene system. There was a metal-to-insulator transition after adsorption of the aryl groups for the zigzag GNRs. © 2014 Author(s).