Monocrystalline Heusler Co2FeSi alloy glass-coated microwires: Fabrication and magneto-structural characterization

Abstract Large scale production of single crystalline phase of Heusler Co 2 FeSi alloy microwire is reported. The long microwire (∼1 km) with the metallic nucleus diameter of about 2 µm is characterized by well oriented monocrystalline structure ( B2 phase, with the lattice parameter a  = 5.615 A). Moreover, the crystallographic direction [1 0 1] is parallel to the wire’s axis along the entire length. Additionally, the wire is characterized by exhibiting a high Curie temperature ( Tc  > 800 K) and well-defined magnetic anisotropy mainly governed by shape. Electrical resistivity measurement reveals the exponential suppression of the electron-magnon scattering which provides strong evidence on the half-metallic behaviour of this material in the low temperature range.