Potential room temperature ferromagnetic O/BN and F/BN bilayers.

Using the full potential linearized augmented plane wave method, we have investigated the magnetic properties of a hexagonal boron nitride (h-BN) monolayer induced by a 0.5 monolayer of oxygen (O) and fluorine (F). It has been observed that the F and O adlayers are adsorbed on the boron top site in the most stable structure. We find that both systems display ferromagnetic ground states. In F/BN, the calculated magnetic moments of F and N atoms are 0.18 and 0.44 μ(B), respectively. Also, the band structure of F/BN is very close to half-metallic. This result is fundamentally different from that found with the pseudo-potential method (Zhou et al 2010 Phys. Rev. B 81 085442). In O/BN, the calculated magnetic moments of O and N atoms are 0.91 and 0.4 μ(B), respectively. The calculated band structure shows a metallic state. Using mean-field theory, the estimated Curie temperature is about 185 K when we assume a three-dimensional interaction. Very interestingly, it has been found that the O/BN may show a ferromagnetic ground state far beyond room temperature. In addition, the calculated x-ray absorption spectroscopy and x-ray magnetic circular dichroism are presented.