We present a novel comprehensive first-principles theoretical study of theelectronic properties and relative stabilities of edge-oxidized zigzag graphenenanoribbons. The oxidation schemes considered include hydroxyl, carboxyl,ether, and ketone groups. Using screened exchange density functional theory, weshow that these oxidized ribbons are more stable than hydrogen-terminatednanoribbons except for the case of the etheric groups. The stable oxidizedconfigurations maintain a spin-polarized ground state with antiferromagneticordering localized at the edges, similar to the fully hydrogenatedcounterparts. More important, edge oxidation is found to lower the onsetelectric field required to induce half-metallic behavior and extend the overallfield range at which the systems remain half-metallic. Once the half-metallicstate is reached, further increase of the external electric field intensityproduces a rapid decrease in the spin magnetization up to a point where themagnetization is quenched completely. Finally, we find that oxygen containingedge groups have a minor effect on the energy difference between theantiferromagnetic ground state and the above-lying ferromagnetic state.
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