Half-metallic ferromagnetism in the zinc-blende MC (M = Li, Na and K)

The electronic structure and magnetic properties of zinc-blende structure MC (M = Li, Na, and K) are investigated by using the first-principles full-potential linearized augmented plane-wave method. The results show that LiC, NaC and KC are half-metallic ferromagnets with a magnetic moment of 3μB per formula unit. The half-metallicity is also found to be robust with respect to the lattice compression and is maintained up to the lattice-constant contraction of 11% and 20% for ZB NaC and KC, respectively. The large magnetic moment and robustness of half-metallicity with respect to the lattice contraction make these materials possible candidates for spin injection in spintronic devices