Materials design of half-metallic graphene and graphene nanoribbons

Through patterned chemical modification, we show that both graphene sheets and zigzag-edged graphene nanoribbons (ZGNRs) can be converted to half-metals as long as the unmodified carbon strip (or width of ZGNRs) is sufficiently wide. Periodically functionalized graphene can mimic electronic behavior of edge-modified ZGNRs as the edge-modified zigzag carbon chains effectively divide a graphene sheet into a series of identical ZGNRs.