Exploration of magnetism in armchair graphene nanoribbons with radical groups

Magnetism of armchair graphene nanoribbons attached with O, CH2, or NH radical groups are investigated within the framework of density functional theory. A variety of interesting band structures of semimetals, spin gapless semiconductors, and semiconductors are obtained. Among the three radical groups considered, CH2 can induce the strongest magnetism with 2 μ B magnetic moment per group. The magnetism is found to come from the unsaturated states on the C atoms at the edges and in the radical groups. No spin polarization is triggered in the ribbons with NH radicals. Our study provides a possible way to carry out d 0 magnetism in armchair graphene nanoribbons.