Possible half-metallic ferromagnetism in zinc blende CrSb and CrAs (invited)

Theoretical study based on a first-principles band structure calculation is carried out for new room-temperature ferromagnets, zinc blende CrSb and CrAs. It is found from the total-energy calculation that the ferromagnetic state is energetically favorable for both materials. By using the value of the difference in total energy between ferromagnetic and the antiferromagnetic states, the Curie temperatures of these ferromagnets are estimated as 1600-1800 K within mean-field approximation of the Heisenberg model. The magnetic moment is evaluated to be 3 Bohr magnetons per formula unit for both materials, which agrees well with the saturation moments estimated experimentally. Furthermore, these ferromagnets are half metallic, and the spin polarization at the Fermi level is almost unaffected even if spin-orbit interaction is taken into account. (C) 2003 American Institute of Physics.