The role of size in spin properties of zigzag graphene nanoribbon

摘要

The effects of ribbon size on the spin properties of zigzag graphene nanoribbon (ZGNR) with and without edge pentagon-heptagon reconstruction are investigated using spin-polarized density functional theory. It is found that when ribbon width is less than 26.31 ?, the Coulomb and RKKY-like interaction between two ribbon-edges result in the edge state splitting. For a wider ZGNR, the interedge coupling is negligible. In addition to stabilizing the system and weakening the interedge coupling, the edge pentagonheptagon reconstruction could demagnetize the ZGNR. In perfect and single-edge reconstructed ZGNR, the magnetic moment depends on ribbon width, and the change of magnetic moment becomes inconspicuous with increasing ribbon width. Double-edge reconstructed ZGNR shows nonmagnetic. It may be useful for fabricating graphene-based nanoelectronic and spintronic devices.