Defective graphene and nanoribbons: electronic,magnetic and structural properties

We make use of first-principles calculations, based on the density functional theory(DFT), to investigate the alterations at the structural, energetic, electronic andmagnetic properties of graphene and zigzag graphene nanoribbons (ZGNRs) due to theinclusion of different types of line and punctual defects. For the graphene it is foundthat the inclusion of defects breaks the translational symmetry of the crystal withdrastic changes at its electronic structure, going from semimetallic to semiconductor andmetallic. Regarding the magnetic properties, no magnetization is observed for thedefective graphene. We also show that the inclusion of defects at ZGNRs is a good way tocreate and control pronounced peaks at the Fermi level. Furthermore, defective ZGNRsstructures show magnetic moment by supercell up to 2.0μ_B. For the non defectiveZGNRs is observed a switch of the magnetic coupling between opposite ribbon edges from theantiferromagnetic to the ferrimagnetic and ferromagnetic configurations.