▎ 摘　　要

Nitrogen doping is a promising approach to induce the basal-plane localized magnetic moments in sp-electron-only graphene sheets. Enhancing the magnetic couplings among the moments can contribute to the high Curie temperature T-C and large ratio of ferromagnetism (FM), which is vital for real applications in spintronic devices; however, it is still challenging. Here, we experimentally demonstrate that graphitic nitrogen (N-Q) could enhance the ferromagnetic couplings of localized magnetic moments provided by the defective N in nitrogen-doped graphene (NG). Nearly pure FM at 2 K is obtained in NG(16.04 )(N-Q/N = 16.04 at. %) with a T-C up to 397.5 K, while the room-temperature saturated magnetization is high as similar to 0.4 emu/g. The rich C -> N electrons contributed by the high ratio of the N-Q complex dominantly devote itinerant magnetism and enhance the interactions among the pyrrolic N (N-5) and/or pyridinic N complexes. Our density functional theory simulation results provide the configurations of (trimerized N-5)-triazinic N-Q along certain directions with enhanced sublattice-independent FM, which are proposed to be the magnetic structures in NG(16.04). Our investigation reveals that introducing the N-Q can serve as an ideal route for the long-range spin correlations and thus full ferromagnetic couplings in graphene.