Intermetallic Co₂FeIn Heusler Alloy Nanowires for Spintronics Applications

Cylindrical Co2FeIn Heusler alloy nanowires are synthesized via template-assisted electrochemical deposition into the hexagonally self-ordered nanopores of hard-anodic alumina membranes. The electroplated nanowires, with 180 ± 20 nm in diameter and ∼14.5 μm in length, exhibit a polycrystalline nature, and they are homogeneous in composition. High-resolution transmission electron microscopy, selected area electron diffraction, and X-ray diffraction analysis confirmed a cubic A2 disordered phase of the ferromagnetic Heusler compound, with a lattice parameter of a = 5.764 ± 0.001 Å. In addition, these structural characterizations reveal that the Co2FeIn nanowires display a polycrystalline structure with a pronounced {220} texture. The temperature-dependent magnetization behavior and anisotropy field distribution calculations display a dominant role of shape, magnetocrystalline, and magnetoelastic terms on the effective magnetic anisotropy of Co2FeIn alloyed nanowire arrays. Magneto-optical Kerr effect measurements performed on single freestanding nanowires, after releasing from the hosting alumina templates, confirmed competing behavior between shape and magnetocrystalline anisotropy contributions, which lead to complex magnetization reversal process. This fabrication technique offers a promising and new forward-looking synthesis of novel Heusler nanomaterials for spintronics applications.