Intermetallic Co₂FeIn Heusler Alloy Nanowires for Spintronics Applications

Abstract

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 around 14.5 µm in length, exhibit a polycrystalline nature and they are homogenous in composition. High-resolution transmission electron microscopy (HR-TEM), selected area electron diffraction (SAED) and Xray diffraction (XRD) 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.

Recent Advances in Nanoporous Anodic Alumina: Principles, Engineering, and Applications

“…Depending on the membrane geometry, different magnetic anisotropy was obtained. The shape of NAA is also favorable for the production on nano brushes in flat and spatial (3D) configurations [ 10 , 225 ] as well as liberated nanowires [ 226 , 227 ]. However, while reports demonstrate many different combinations of materials and shape, a significant fraction remains on the concept stage.…”

Optical and Electrochemical Characterization of Nanoporous Alumina Structures: Pore Size, Porosity, and Structure Effect

“…Nanoporous alumina structures (NPASs) obtained by electrochemical anodization of aluminum foils according to the two-step anodization method [1,2] are of great interest due to their application as nanofilters, drug deliverers, templates for nanoparticles, nanotubes, nanowires, platforms for sensors, and medical devices [3][4][5][6][7][8][9]. Lately, other applications of NPASs such as spintronics, solar cells, light emitting diodes, and photonic crystals have been studied [10][11][12][13][14][15][16]. Most of these applications are related to the high structural regularity of NPAS, which exhibit almost ideal cylindrical pores with narrow pore radius distribution and without tortuosity, but their thermal and chemical resistance are also of great interest when used as nanofilters or membranes due to their stability under cleaning protocols commonly used to reduce fouling (adsorption/deposition of transported molecules or particles), which is the main problem in such applications [17,18].…”

Functional Gradient Transparent Conducting Oxide Nanowire Arrays as Monophasic Schottky-Barrier Free Memristors for Bipolar Linear Switching

“…[29] Because the deposition potentials of Sn 2+ → Sn 0 (E = -0.9V) and Sb 3+ → Sb 0 (E = -0.95V) are close together (see Supporting Information Figure S3), co-deposition should be possible. [30] There is only one cathodic peak at -0.95 V in the CV of the mixture. This observation is consistent with alloy formation.…”