Magnetism in carbon nanoscrolls: Quasi-half-metals and half-metals in pristine hydrocarbons

Abstract

A magnetic ground state is revealed for the first time in zigzag-edged carbon nanoscrolls (ZCNSs) from spinunrestricted density functional theory calculations. Unlike their flat counterpart-zigzag-edged carbon nanoribbons, which are semiconductors with spin-degenerate electronic structure-ZCNSs show a variety of magnetic configurations, namely spin-selective semiconductors, metals, semimetals, quasi-half-metals, and half-metals. To the best of our knowledge, this is the first discovery of quasi-half-metals and half-metals in a pure hydrocarbon without resort to an external electric field. In addition, we calculated the spin-dependent transportation of the semiconducting ZCNSs with 12 and 20 zigzag chains, and found that they are 13% and 17% at the Fermi level, respectively, suggesting that ZCNS can be an effective spin filter. © Tsinghua University Press and Springer-Verlag 2009.