Electrochemical synthesis and magnetic properties of single-crystal and netlike poly-crystal Ni nanowire arrays

Sci. China Phys. Mech. Astron.

et al. 2011

Highly textured Ni nanowire arrays were fabricated into anodic aluminum oxide (AAO) templates by pulse DC electrodeposition. The applied voltage and pH value of electrolytes were found strongly affecting the microstructure and magnetic properties of Ni nanowire arrays. Low applied potential and pH value both prefer to form polycrystalline fcc Ni nanowires. Increasing the applied potential or pH value favors the Ni [220] texture and even eventually forms the [220] oriented single crystal Ni wires, while exorbitant potential and pH value will conversely weaken the texture of nanowires. The magnetic properties of Ni wires are closely related to the microstructure of Ni nanowire arrays and large coercivities more than 1000 Oe were achieved at single crystalline Ni nanowire arrays. The mechanisms for the effect of applied potential and pH value on the grain size, texture and magnetic properties of Ni nanowire arrays have been discussed. nanowire arrays, applied potential, pH value, microstructure, magnetic properties, electrodeposition PACS: 07.55.-w, 07.55.Jg, 07.50.-eElectrodepositing elements into anodic alumina oxide (AAO) templates provides a simple technique to obtain the highly ordered nanowire arrays [1-3]. The low-cost AAO films are thermally stable at high temperature and the pore channels they contain are of uniform size, parallel to each other and perpendicular to the film surface. Furthermore, it is also comparatively easy to control the wire dimensions and the areal density of pores by adjusting the anodizing parameters (e.g. voltage, electrolytes and temperature) [1,2]. These features have attracted considerable interests in recent years due to the potential applications in ultra-highdensity magnetic recording, catalysts, nanoscale electronic and optoelectronic devices [4,5]. However, a well-controlled growth of nanowires is necessary for the successful application in devices. Tian et al. [6] have reported that if lower overpotential is used during DC electrodeposition then single crystalline nanowires of noble metals such as Au, Ag, Cu can be grown, but it is difficult to grow single crystalline nanowires of high melting point metals such as Co, Ni, Rh. Nevertheless, Yue et al. have found [7] that the lower potential is essential for the growth of single crystalline Ni nanowire arrays. Conversely, Pan et al. [8] and Thongmee et al. [9] have indicated that a higher overpotential favors the growth of single crystalline nanowires of Ni, Zn, Cu and Co. Clearly, the formation of single crystalline nanowires is not as easily explained only by overpotential. In recent literature, Kockar et al. [10] have reported that the magnetic properties of continuous Ni films are very sensitive to the electrolyte pH value. However, up to now, there are relatively few reports [7] studying the effect of pH value on the structure and magnetic properties of Ni nanowires. In this work, we investigated the influences of both potential and pH value on the microstructure and magnetic properties of Ni nanowire arrays by pulse ...

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confidence: 99%

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confidence: 99%

Growth and magnetic properties of single crystalline Ni nanowire arrays prepared by pulse DC electrodeposition

Zhang

Jin

Sci. China Phys. Mech. Astron.

et al. 2011

“…Among these methods, template-assisted electrodeposition is a popular way to obtain uniform and highly ordered nanowire arrays [12,13]. The nucleation and growth kinetics of the nanowire arrays in one-dimensional confined geometry can be tuned by different experimental parameters, including template dimension, electrolyte properties (pH value, composition, additive, and so on), reaction temperature, applied voltage, and the current density [14][15][16][17]. In our previous work, we demonstrated that current density can influence the growth direction and crystalline quality of electrodeposited semiconductor nanowire arrays, and further change their photoluminescence properties [18,19].…”

Section: Introductionmentioning

confidence: 99%

Orientation Growth and Magnetic Properties of Electrochemical Deposited Nickel Nanowire Arrays

et al. 2019

Catalysts

Highly ordered ferromagnetic metal nanowire arrays with preferred growth direction show potential applications in electronic and spintronic devices. In this work, by employing a porous anodic aluminum oxide template-assisted electrodeposition method, we successfully prepared Ni nanowire arrays. Importantly, the growth direction of Ni nanowire arrays can be controlled by varying the current densities. The crystalline and growth orientation of Ni nanowire arrays show effects on magnetic properties. Single-crystallinity Ni nanowires with [110] orientation show the best magnetic properties, including coercivity and squareness, along the parallel direction of the nanowire axis. The current preparation strategy can be used to obtain other nanowire arrays (such as metal, alloy, and semiconductor) with controlled growth direction in confined space, and is therefore of broad interest for different applications.

“…Recently, high-quality metal one-dimensional (1D) nanostructures, such as nanowires or nanotubes, have been considered as novel systems for their potential applications in sensing, electronic, and optical devices due to their high surface area-to-volume ratio . Many different approaches for the preparation of these coinage metal nanomaterials (such as Cu and Ni) include but are not limited to electrospinning, electrochemical deposition, UV photolithography, hydrothermal processes, liquid phase reduction, and chemical vapor deposition (CVD) methods. ,− However, while these techniques can successfully generate these nanomaterials, a step forward synthetically speaking would be to possibly mitigate for the use of specialized instrumentation (e.g., lithography), high energy processing (e.g., CVD), or potentially toxic precursors (i.e., hydrazine in conventional wet chemistry protocols) in order to synthesize pure, monodisperse, and crystalline Cu or Ni nanostructures.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, Characterization, and Formation Mechanism of Crystalline Cu and Ni Metallic Nanowires under Ambient, Seedless, Surfactantless Conditions

Lewis

Crystal Growth & Design

Liu

et al. 2014

In this report, crystalline elemental Cu and Ni nanowires have been successfully synthesized through a simplistic, malleable, solution-based protocol involving the utilization of a U-tube double diffusion apparatus under ambient conditions. The nanowires prepared within the 50 and 200 nm template membrane pore channels maintain diameters ranging from ∼90−230 nm with lengths attaining the micrometer scale. To mitigate for the unwanted but very facile oxidation of these nanomaterials to their oxide analogues, our synthesis mechanism relies on a carefully calibrated reaction between the corresponding metal precursor solution and an aqueous reducing agent solution, resulting in the production of pure, monodisperse metallic nanostructures. These as-prepared nanowires were subsequently characterized from an applications' perspective so as to investigate their optical and photocatalytic properties.