Preparation and nanoscale characterization of electrodeposited CoFe-Cu multilayer nanowires

• Published in: Materials chemistry and physics Vol. 230; pp. 231 - 238
• Main Authors: Agarwal, Shivani, Pohl, Diana, Patra, Ajit Kumar, Nielsch, Kornelius, Khatri, Manvendra Singh
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15-05-2019; Elsevier BV
• Subjects: AAO template; Aluminum oxide; Anisotropy; Aspect ratio; Coercivity; CoFe-Cu multilayer; Copper; Freezing; Magnetic measurement; Magnetism; Microscopy; Multilayers; Nanowires; Pulse electrodeposition; Scanning electron microscopy; Shape anisotropy; Temperature dependence; Thickness; Transmission electron microscopy; Variations; CoFe-Cu multilayer; AAO template; Shape anisotropy; Pulse electrodeposition; Coercivity
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2019.03.065

CoFe-Cu multilayered nanowires have been fabricated by pulse electrodeposition into the pores of ∼100 nm diameter anodized aluminum oxide (AAO) templates. Here, we investigate three samples, where the magnetic layer thickness is increased by extending the pulse time tCoFe 10 s, 13 s and 16 s while keeping the non-magnetic layer thickness constant (tCu = 30 s). Scanning electron microscopy and transmission electron microscopy confirm uniform, continuous and densely packed wires. By increasing the CoFe deposition time the aspect ratio enhanced and a layer stacking is demonstrated. The EDX line scan along the single nanowire indicates that they are Cu-rich with the composition of 10–15% Co, 0–5% Fe and 75–80% Cu. Magnetic measurements reveal a temperature dependency of the coercivity. The increase in coercivity is associated with the inherent shape and magnetocrystalline anisotropy of the nanowires. Magnetic measurements at low temperature exhibited the increase in coercivity of CoFe-Cu nanowires as a result of the freezing of thermal fluctuations.
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•CoFe-Cu multilayer nanowires have been synthesized by pulse electrodeposition technique.•TEM confirmed good morphology and stacked layers.•X-ray diffraction confirms the formation of bcc structure.•High value of coercivity is observed parallel to wire axis.