Electronic and magnetic properties of oxygen patterned graphene superlattice

Graphene superlattices formed by adsorbing oxygen lines on graphene are studied using spin-polarized density functional theory calculations. It is found that separating zigzag chains (armchair dimer lines) with one oxygen adsorbate on each periodic segment of the chain (line) are sufficient to divide the graphene sheet into series of graphene nanoribbons. The energy band gap of the graphene with armchair (zigzag) oxidation lines (chains) is modulated with line (chain) separation as the width modulation of the freestanding graphene ribbon. The magnetic properties of superlattices with different oxidized line width for both zigzag and armchair oxidized lines are also investigated. Magnetism is found in oxygen-patterned graphene superlattice with zigzag interface and is enhanced with the increasing width of separating oxidation chains. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4769743]