Half-Metallicity and Stability of Ferromagnetism in (Fe_1−xCo_x)₂CrZ (Z=s, p Elements)

Abstract

The half-metallicity and the stability of the ferromagnetic state have been investigated in the Heusler type alloys (Fe_1−xCo_x)₂CrZ (Z=s, p elements). If only the ferromagnetic state is assumed as the magnetic state of Fe₂CrZ, the half-metallicity tends to appear easily as the total number of the valence electrons and the lattice constant decrease. Taking the paramagnetic and the antiferromagnetic state into account, it is predicted that Fe₂CrSi and Fe₂CrP may be half-metals among Fe₂CrZ. However, if the Co atoms are partially substituted for the Fe atoms in Fe₂CrZ (Z=Al, Si, P, Ge, Sn), the ferromagnetic state tends to become more stable as the Co composition increases, without losing the half-metallicity. These results suggest that partial substitution of the Co atoms for the Fe atoms is effective in improving the properties as spintronic materials in Fe₂CrZ.