Magnetism in Carbon Nanoscrolls: Quasi-Half-Metals and Half-Metals in Pristine Hydrocarbons

A magnetic ground state is revealed for the first time in zigzag-edged carbon nanoscrolls (ZCNSs) from spin-unrestricted 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.