Materials design of Cr-based half-metallic ferromagnets

Electronic band-structure of zinc-blende (zb) chromium monopnictides, CrP, CrAs, and CrSb, as well as chalcopyrite-type CrGeP₂ is studied comparatively by using first-principles density-functional calculations. It is found that the ferromagnetic state is energetically favorable for all these materials. Both zb-CrAs and CrSb are predicted to be half-metallic, while the spin-polarization at the Fermi-level is quite small for zb-CrP and CrGeP ₂. Highly spin-polarized electronic band-structures in zb-CrAs and CrSb are almost unaffected, even if the spin-orbit interaction is taken into account.