Synthesis and intrinsic magnetism of bilayer graphene nanoribbons

Graphene nanoribbons (GNRs) can be an excellent spin semiconductor for the existence of both the localized edge states and intrinsic bandgap. Despite that the magnetism of single and multi-layer GNRs have been widely investigated before, the situation of bilayer GNRs (BLGNRs) is entirely unknown experimentally. Inspired by the potential applications in spintronics, here we report the synthesis of pristine BLGNRs with the average width of ca. 9 nm by longitudinal unzipping the oxalic acid-intercalated double-walled carbon nanotubes followed by annealing at 900 degrees C. The magnetic properties of BLGNRs were investigated. The results reveal that BLGNRs show obvious antiferromagnetic behavior with the Neel temperature of ca. 66 K. It is proposed that (i) the spin-polarized edge states are the dominant magnetic source, and (ii) the antiferromagnetism is mainly caused by the interlayer couplings. (C) 2018 Published by Elsevier Ltd.