High Spin Polarization in Co₂FeSn Heusler Nanowires for Spintronics

Cylindrical nanowires made of Co2FeSn Heusler alloy with high spin polarization have been synthetized via template-assisted electrochemical deposition in nanoporous anodic alumina membranes. Their microstructure and morphology have been characterized by in situ studies of X-ray diffraction, together with scanning and transmission electron microscopy techniques. The basic structural and magnetic characterization revealed a B2-type cubic ordered Heusler structure with a lattice parameter of around 5.8 Å and the [110] direction, preferably aligned with the longitudinal axis of the polycrystalline nanowires. The easy magnetization axis is parallel to the nanowire’s axis too. The point-contact Andreev reflection spectroscopic measurements performed on the nanowire’s fresh surface released high polarization values, that is, P = 0.85–1, and prove that the high spin polarization or half-metallicity will be preserved in the nanoscale regime. The presented results open the possibilities toward future exploration of Heusler nanowires with high spin polarization, which are promising materials for applications in spintronics and high-density magnetic data recording.