Half-metallic magnetism in triazines g-C4N3and g-C3N4tailored with H, Li, and 2p elements

Abstract

The graphitic carbon nitride g-C4N3, since its experimental realisation, and particularly being proven a free - standing monolayer with half - metallic ferromagnetism, has drawn growing research interest in spintronics. Here, the author presents a study using density functional calculations, on the electronic structure and magnetic ordering of g-C4N3 and its sister monolayer triazine g-C3N4, tailored with H, Li, and 2p elements. Half-metallic ferromagnetism of pristine g-C4N3 is first elucidated with an emphasis on its localised spin magnetic moments due to pyridinic N-sp2 electrons. The author then proposes various scenarios tailoring the structure of these two materials, in order to induce itinerant magnetism therein, towards greater potential applications in spintronics. The key to that problem lies in the chemistry of H, Li, and other 2p atoms at the graphitic N or C and vacant sites of our crystal lattices. Interestingly, in certain elaborate scenarios involving pairs of 2p adatoms at the latter, the author have obtained new half-metallic material structures where both localised and itinerant magnetism mechanisms coexisted. This result is explained in a clear physicochemical picture where the effect of spin - charge transfer shapes the electronic structures of these new monolayers.