M-C21, an anti-ferromagnetic carbon bulk materials

Abstract A new carbon allotrope named M-C21 with anti-ferromagnetic ground state is predicted and theoretically studied by Ab initio density functional theory (DFT) method. This new structure displays F-43 M space group for the non-magnetic and ferromagnetic states and IMM2 space group for the anti-ferromagnetic state. The magnetic property in the M-C21 carbon origins from the space confined carbon radicals, which couples with the nearby magnetic carbon atoms through super-exchange mechanism. The M-C21 carbon could be possibly synthesized through dehydrogenation from the mixture of Centro-hexaquinacene and methane. This work provides a new theoretic solution for the design and synthesis the magnetic carbon materials for future applications.