Electronic structures, magnetism, and half-metallicities of full-Heusler Fe2-xCoxCrAl (x=0,1,2) alloys

We have investigated the electronic structures, magnetism, and half-metallicities of full-Heusler Fe_2-xCo_xCrAl (x=0,1,2) alloys by using the all-electron full-potential linearized augmented plane-wave method within the generalized gradient approximation. From the calculated total energies for the three types of FeCoCrAl systems, it is found that the FeCoCrAl-III system is energetically most favorable. It is found, from the calculated density of states, that the Fe₂CrAl and Co₂CrAl alloys clearly show half-metallic character. We also found that the FeCoCrAl-III is half-metallic while the other two systems are nearly half-metallic from the minority density of states at the Fermi level. The calculated magnetic moments of FeCoCrAl-III for Fe, Co, and Cr atoms are 0.95, 1.07, and 1.93 μ_B, respectively, larger than those of the other two systems.