Shuffle dislocation induced magnetic moment in graphene

[EN] Graphene, a honeycomb arrangement of carbon atoms, is a promising material for nanoelectronics applications due to its unusual electronic properties. Recent experiments performed on suspended graphene indicate the existence of intrinsic defects on the samples. It is known that lattice defects such as vacancies or voids leaving unpaired atoms, lead to the formation of local magnetic moments (Vozmediano et al., 2005 [1]). The existence and ordering of these moments is largely determined by the bipartite character of the honeycomb lattice seen as two interpenetrating triangular sublattices. Dislocations made by pentagon-heptagon pairs or octagons with an unpaired atom have been studied recently and found to be stable in the graphene lattice (Carpio et al., 2008 [2]). These defects frustrate the sublattice structure and affect the magnetic properties of graphene. We study the magnetic properties of graphene in the presence of these defects. The system is described by a pz tight-binding model with electron-electron interactions modelled by a Hubbard term. Spin-polarized mean-field solutions are investigated within an unrestricted Hartree-Fock approximation. © 2009 Elsevier B.V. All rights reserved.