Half-metallic and magnetic properties in nonmagnetic element embedded graphitic carbon nitride sheets

We have investigated the structures, electronic structures and magnetic properties of the triazine-based g-C3N4 (gt-C3N4) monolayer doped with B, Al, and Cu atoms based on density functional theory using ab initio calculations. The B atom prefers to be situated at the center of the triazine ring, whereas the Al and Cu atoms tend to be located above the center of the triazine ring. The doping at the interstitial sites results in nonplanar structures which are thermodynamically stable. Each dopant atom induces a total magnetic moment of 1.0 μB which mainly arises from the pz orbitals because the n-type doping injects unpaired electrons into anti-π orbitals. The results obtained from the GGA-PBE and HSE06 schemes show that all the doped systems exhibit half-metallic behaviors. B- and Al-doped systems are at a ferromagnetic ground state, while the Cu-doped case is at an anti-ferromagnetic ground state. The long-range half-metallic ferromagnetic order is attributed to the p-p interactions. In particular, the estimated Curie temperature implies that the systems doped with B are potential candidates for spintronics applications in future.