Structural stability, magneto-electronics and spin transport properties of triangular graphene nanoflake chains with edge oxidation

Tuning the magneto-electronic properties of graphene-based structures into distinguished performance is an interesting but challenging work. To address this issue, we here construct several chain-like 1D nanostructures by stitching zigzag-edged triangular graphene nanoflakes with different manners and subsequently oxidized at edges. The high stability of these structures is identified by the calculated edge adsorption energy, phonon spectrum, and molecular dynamics simulations. Unlike edge-hydrogenation case, termination oxygen atoms here are highly magnetized and can control such 1D chain magneto-electronic features substantially. The calculations predict that such 1D chains are very versatile, and behaviors are sensitive to geometry, likely acting as a ferromagnetic metal and half-metal and bipolar magnetic semiconductor, or an antiferromagnetic metal and semiconductor. In particular, such a ferromagnetic half-metallic feature can occur in the ground state and possesses a wide bandgap, suggesting that they are excellent magnetic materials. The calculated spin transport characteristics reveal that such a chain-based device promises not only a perfect double spin-filtering effect, but also an excellent dual spin diode feature and a giant magnetoresistance (GMR) effect. The advantages over graphene nanoribbons are thus expected.

The detailed calculations predict that the edge-oxidized 1D zigzag-edged triangular graphene nanoflake chains are excellent magnetic materials, acting as a ground-state ferromagnetic half-metal and holding a promising magnetic device feature.300