A new Heusler compound Cu₂FeAl: Electronic structure, magnetism and transport properties

The new ferromagnetic Heusler alloy of Cu₂FeAl has been prepared by melt spinning. The band-structure calculations on this alloy predict a ferromagnetic ground state and the crystal structure not to be stable. The intrinsic properties of Cu₂FeAl ribbons are described from magnetic and transport measurements. The electronic structure calculations show that the magnetic moment of Cu₂FeAl is not localized, which is not the same as Cu₂MnAl. At low temperature, the magnetization decreases as T ^3/2, as can be well interpreted by spin-wave theory. An interpretation is given for the electrical resistivity and leads to information about the microscopic scattering mechanisms involved. A negative longitudinal magnetoresistance of less than 1% at high field is observed, which can be qualitatively explained by s-d interaction. The magnetic resistivity is estimated for this compound.