Phase separation and magnetic properties of half-metal-type Co2Cr1−xFexAl alloys

The phase stability and magnetic properties of the half-metal-type ${\mathrm{Co}}_2{\mathrm{Cr}}_{1-x}{\mathrm{Fe}}_x\mathrm{Al}$ alloy system were investigated. It was found that the occurrence of two-phase separation is unavoidable in a concentration range of less than $x=0.4$ , leading to deviation of the saturation magnetic moments from the generalized Slater–Pauling line. The $L{2}_1$ -type phase becomes stable in a concentration range of more than $x=0.7$ , where no half-metallic behaviors are present. Consequently, it is concluded that the most favorable concentration for applications to spintronic devices is located around $x=0.4$ in ${\mathrm{Co}}_2{\mathrm{Cr}}_{1-x}{\mathrm{Fe}}_x\mathrm{Al}$ alloys having the $B2$ -type phase.