Edge reconstruction induces magnetic and metallic behavior in zigzag graphene nanoribbons

The edge reconstruction of zigzag graphene nanoribbons to a stable line of alternatively fused seven and five membered rings with hydrogen passivation has been studied within density functional theory with both localized and extended basis approximations. Reconstruction of both edges results in a nonmagnetic metallic ground state, whereas the one edge reconstruction stabilizes the system in a ferromagnetic metallic ground state. The reconstructed edge suppresses the local spin density of atoms and contributes finite density of states at Fermi energy. Our study paves a new way to fabricate the metallic electrodes for semiconducting graphene devices with full control over the magnetic behavior without any lattice mismatch between leads and the channel.