Ni Nanowires Research Articles

Vertically Integrated Nanowires on Si Wafers and Into Circuits

Vertically integrated copper (Cu) and nickel (Ni) nanowires (NWS) were fabricated on silicon using anodized aluminum oxide (AAO) thin film templates integrated onto silicon wafers. Both the AAO and NWs were mechanically robust and demonstrated to withstand further fabrication processes used for integrated circuits. The AAO pores were measured to be ~30 nm with size distributions narrowing from ±12 to ±6 nm after a second anodization. The NWs, therefore, had similar diameters and distributions inside these integrated AAO films. Magnetic hysteresis loops demonstrated the out-of-plane anisotropy of the vertically oriented Ni wires in the presence of pore outgrowth that had in-plane anisotropy. When used as vias and integrated with coplanar waveguides (CPWs), the Cu NWs had lower losses than standard vias above 60 GHz.

Effects of twin orientation and twin boundary spacing on the plastic deformation behaviors in Ni nanowires

• Effects of twin orientation (θ) on the Ni nanowire (NW) ductility are investigated • NW ductility with θ ∼55° increases with decreasing twin boundary (TB) spacing • In-situ TEM reveals distinct deformation behaviors in NWs with different θ • Atomistic observation reveals different roles of TB can play during deformation • The different ductility can be related with microscopic deformation mechanisms Spreading twins throughout nano metals has been proved to effectively mediate the mechanical behaviors in face-centered-cubic (fcc) metals. However, the experimental investigation concerning the roles of twin boundary (TB) during deformation is rarely reported. Here, with the joint efforts of in-situ nanomechanical testing and theoretical studies, we provide a systematic investigation regarding the effects of TB orientation ( θ , the angle between tensile loading direction and the normal of TB) and spacing on deformation mechanisms in Ni nanowires (NWs). As compared with single-crystalline counterparts, it is found that nano-twinned (nt) NWs with θ ∼0° exhibit limited ductility, whereas TB can serve as an effective blockage to the dislocation propagation. In contrast, in nt NWs with θ ∼20° and 55°, TB migration/detwinning induced by TB-dislocation reaction or partial dislocation movement dominates the plasticity, which contributes to enhanced NW ductility. Regarding nt NWs with θ ∼90°, dislocations are found to be able to transmit through the TBs, suggesting the limited effect of TB on the NW stretchability. Furthermore, decreasing TB spacing ( λ ) can facilitate the detwinning process and thus greatly enhance the ductility of NW with θ ∼55°. This study uncovers the distinct roles that TB can play during mechanical deformations in fcc NWs and provides an atomistic view into the direct linkage between macroscopic mechanical properties and microscopic deformation modes.

Влияние фрактальности никелевой наносети на ее магнитные свойства

The magnetic properties of a nanonetwork consisting of ultrathin Ni nanowires (diameter < 4 nm) and Ni nanoballs (diameter < 20 nm) are studied at different stages of its growth during laser ablation in a superfluid helium medium. It has been established that, at the early stages of ablation, the nanonetwork consists mainly of nanowires and has a rectangular magnetic hysteresis loop. At the late stages of ablation, the concentration of nanoballs and their diameter increase, and the shape of the hysteresis loop deviates from a rectangular one. The fractal dimension of the nanonetwork is determined, which varies from 1 in the early stages of ablation, when individual nanowires occur, to 2, when the nanonetwork becomes so dense that it is a continuous film. It is shown that the saturation magnetization changes with a change in the fractality of the nanonetwork, which, under constant ablation conditions, is explained by the transformation of nanowires into nanoballs during their folding.

Nanosurface-induced construction of NiCoP–CoP heterostructure nanobristle electrodes for highly efficient alkaline hydrogen evolution reaction

NiCoP-CoP@NNA is a hierarchical heterostructured HER catalyst prepared by Ni solid-state diffusion from Ni nanowire substrate. DFT shows that Ni atoms diffuse from nano-sized substrate easily, and the heterostructure has a low water dissociation energy barrier, leading to better HER activity.

Triple‐Asymmetric Flexible Strain Sensor Based on High‐aligned Ni Nanowire Arrays with Opposite Resistance Responding for Multidimensional Motions Detection

AbstractHerein, a triple‐asymmetric flexible strain sensor by using the single‐layered high‐aligned Ni‐nanowire arrays is proposed for the applications of monitoring multidimensional motions of human joints. The triple‐asymmetric structures consist of a spatially ordering distribution of Ni nanowires (NWs) and double position asymmetric distributions of the Ni NWs in width and thickness direction of sensor. Because Ni NWs are isolated from each other, the resistance change of the sensor is by tunneling effect. The resistance values of the proposed sensor decrease with the increasing of stretching strain, which is different from that of the common flexible strain sensors, and the maximum absolute valve of gauge factor is 35. Furthermore, the proposed sensor has a good bending sensitivity, ranging from 90° to −90°, and minimum resolution angle of 5° in out‐plane bending. Benefiting from the asymmetric structures and tunneling effect, the complex movements of human joints (such as up‐down bending, left‐right swing, and rotating of wrist) are successfully detected. The practical applicability in real‐time monitoring and the processes of handwriting are also shown. Therefore, this proposed sensor is believed to have great potential in future development of micro‐motion monitoring, wearable electronics, and artificial intelligence.

Synthesis of nickel-based nanowires induced by different nucleating metals and their applications in ammonia borane hydrolysis

A straightforward method was developed to synthesize Ni-Mseed (M = Pt, Pd, Au, Ru, Ag, Cu) nanowires (NWs) under magnetic field using different metal cations as nucleating agents. The type of nucleating agents affected more on the average diameter of the produced Ni-Mseed NWs, which varied from tens to hundreds of nanometers. Physical measurements revealed the presence of nucleating metals with contents less than 1.0 at.% to Ni, indicating them to be small amounts of nucleating metals loaded Ni nanowires rather than a pure Ni material. For the hydrolysis of ammonia borane, the as-prepared Ni-Mseed NWs exhibited exceptional catalytic activities with significantly improved H2 production kinetics compared with the pristine Ni material, demonstrating more promising applications of the Ni-Mseed NWs in catalysis field.

Core-shell structured hierarchical Ni nanowires and NiS/Co3S4 microflowers arrays as a high-performance supercapacitor electrode

To develop new positive electrode materials with high electrochemical performance for practical applications in energy storage, the design of new complex morphologies with a core-shell structure based on MS sulfide materials with M = Ni, Co, Fe or Mn and nanomaterials metallic is a very essential technique. In this study, an asymmetric supercapacitor (ASC) with high energy density was fabricated by combining a NiS/Co3S4@h-Ni NWs battery-like electrode with α-MnO2 as a pseudo-capacitive electrode. Firstly, hierarchical Nickel Nanowires, h-Ni NWs, were prepared by the reduction of Ni2+ ions by hydrazine, and then the h-Ni NWs are coated with NiS/Co3S4 by the hydrothermal method to form a core-shell structure with good electrical conductivity. The electrochemical performance of the NiS/Co3S4@h-Ni NWs electrode was evaluated in the 4 M LiOH electrolyte. The results showed that the NiS/Co3S4@h-Ni NWs electrode had a specific capacity of 1893 C/g at a current density of 1 A/g and an excellent retention of 98.63 % of its initial specific capacity after 10,000 charge-discharge cycles at 20 A/g due to the synergistic interaction between the nickel nanowires and (Ni/Co) sulfides in the developed core-shell structure. Furthermore, the fabricated ASC device provided a high energy density of 101.05 Wh/kg at a power density of 850 W/kg. At a maximum power density of 17 kW/kg, the device provided an energy density of 57.13 Wh/kg along with excellent capacity retention (83.56 %) after 10,000 charge-discharge cycles at 20 A/g.

Fabrication of hierarchical Ni nanowires@ NiCo-layered double hydroxide nanosheets core-shell hybrid arrays for high-performance hybrid supercapacitors.

Layered double hydroxides (LDHs) are electrode materials with high specific capacity due to their structure which has a tunable interlayer spacing, however, the disadvantages of their low conductivity and electrochemically limited sites prevent their application in supercapacitors. In this study, we synthesized a high electrochemical performance electrode material with a core-shell structure based on hierarchical nickel nanowires (core) and NiCo LDHs nanosheets (shell). First, hierarchical nickel nanowires, h-Ni NWs, were prepared by the reduction of Ni2+ ions by hydrazine N2H4. Then with the hydrothermal method, the hierarchical nickel nanowires were coated with NiCo LDHs to improve the electrical conductivity of the latter. The electrochemical results showed that the NiCo LDHs@h-Ni NWs electrode had a specific capacity of 1486 C/g at a current density of 1 A/g in 6 M KOH electrolyte with excellent capacity retention (89.7%) after 10,000 charge-discharge cycles at 20 A/g. Due to the synergistic interaction between nickel nanowires and NiCo LDHs which provides excellent conductivity, durability, efficient mesoporous network, and suitable channels for fast ion/electron transfer. In addition, a hybrid supercapacitor (HSC) was fabricated by combining the NiCo LDHs@h-Ni NWs electrode (battery type) with activated carbon (EDLC). The fabricated device provided a high energy density of 72.22 Wh/kg at 800 W/kg, and a maximum power density of 16 kW/kg, the HSC provided an energy density of 50.44 Wh/kg and outstanding cycling stability (88.1% retention after 10,000 cycles).

Nanostructured Nickel-based Non-enzymatic Electrochemical Glucose Sensors.

Glucose detection is considered a significant area and has remained the topic of considerable attention. Remarkable technological advancements have been observed in diabetes monitoring in the past decades. This continual progress helps to track recent trends in development as well as identify challenging issues in glucose sensor construction. Thus, a comprehensive synopsis of the most recent advancements and developments in the study of nickel (Ni) nanostructure-based sensors for efficient trace-level glucose detection, following non-enzymatic and electrochemical methods, is provided in this review. Moreover, this review is intensively focused on the methodologies for the structure, morphology, preparation, and enforcement of a variety of Ni nanostructures, including Ni nanosheets with metals, Ni nanospheres with metals/mixed metals, Ni-metal nanocomposites, metal nanoparticles-decorated Ni nanowires, Ni nanoparticles, Ni-decorated metal nanotube arrays, Ni nanoneedles and nanorods with metals, nanoporous, nanoplates, nanocoated Ni with metal composites, and Ni-composed hybrid nanostructures. Various demonstrations and categorizations are provided on Ni-based nanostructures for a clear understanding for diverse readers.

Platinum–Nickel Nanowires and Nanotubes Arrays as Carbon-Free Cathodes for the Polymer Electrolyte Membrane Fuel Cell

The cathode is the most crucial component of the polymer electrolyte membrane fuel cell (PEMFC) because it is the most limiting in terms of performance, durability, and cost. Regarding the performance, the main losses are due to the cathode because of the negative coupling between a sluggish oxygen reduction reaction (ORR) and H+ and O2 transport loss issues. Therefore, many efforts have been conducted on the one hand to increase the kinetic of the ORR by developing a catalyst with improved activity and stability. On the other hand, attempts have been made to reduce mass transport losses in the cathode by tuning its nanostructure. This paper describes a multistep process to nanostructure the electrocatalyst in the view of simultaneously benefiting from enhanced activity toward the ORR and reduced O2 transport limitations. Thus, original carbon-free electrode’s architectures made of organized and well-ordered and oriented PtNi nanowires (PtNiNWs) and nanotubes (PtNiNTs) directly embedded onto a Nafion membrane were developed. Here, the nanotubes were templated from Ni nanowires grown on an anodic aluminum oxide (AAO) template. The fabrication process was optimized to improve the quality of the nanotubes and their integration into the membrane: the process includes thermal treatment in a H2/Ar environment and an acid leaching step as key steps to obtain the desired structure. After the electrodes were integrated in a complete membrane-electrode assembly (MEA), we tested the performance and durability of these nanostructures under real operating conditions. We compared the results to a Pt/C conventional electrode at low Pt loading (∼35 μgPt/cm2) exhibiting a roughness factor close to that of PtNiNWs and PtNiNTs electrodes. Results have shown a great improvement in the mass activity and stability of PtNiNTs electrodes in an accelerated stress test. Also, they have shown a significant sensitivity toward relative humidity variation.

FORC-investigation of magnetic properties of Ni nanowire arrays synthesized using Al2O3 templates with different order of pores

FORC-investigation of magnetic properties of Ni nanowire arrays synthesized using Al2O3 templates with different order of pores

Electrodeposition of Nickel From an Amide-Type Ionic Liquid Under a Magnetic Field

Electrodeposition of nickel was investigated in an amide-type ionic liquid, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl) amide (BMPTFSA) containing Ni(TFSA)2 under a external magnetic field. The onset potential of cathodic reduction of Ni(II) with a magnetic field was more positive than that without the magnet field. Ni nanowires were deposited by potentiostatic cathodic reduction with the magnetic field, indicating the magnetic field influence not only the electrode kinetics of the magnetic species but also the morphology of the ferromagnetic metal.

Direct Observation of the Deformation Mechanism of Twin-Structured Ni NWs under Bending Strain

In situ atomic-scale bending tests of twin-structured Ni nanowires were realised using a homemade deformation device. The results showed that the plastic deformation mechanism in twin-structured Ni nanowires depended on the deformation stage. At the early stages of bending deformation, the plasticity of twin-structured Ni nanowires was controlled by dislocations interacting with the twin boundaries or parallel to them. With increasing bending strain, both dislocation and face-centred cubic–body-centred tetragonal phase transition occurred. At very high bending strain, grain boundaries resulting from the lattice distortion/collapse were formed. This study details the deformation mechanisms of the twin-structured Ni nanowires under bending deformation, which advances the basic understanding of the plasticity mechanisms in metals.

Nickel nanobrush platform for a magnetic field-assisted electrochemical response enhancement

A single-step electrochemical procedure to synthesize a brush-like platform, which composed of a nickel nanowire array attached to a nickel continuous layer acting as a solid base, is described. Room temperature hysteresis properties of this brush-like architecture (nanobrush) and those of the individual components (nanowires and layer) are determined. It is shown that the direction of the nanobrush magnetic easy axis may be tailored, being also possible to control the magnetic system's coercivity and remanence. The electrochemical response and the catalytic activity of a Ni nanobrush towards the redox probes [Fe(CN) 6 ] 4-/3- and ethanol were evaluated in the presence and absence of an applied magnetic field. The external field strongly affects the system's behavior by enhancing the electrode charge-transfer response, even at fields as low as 6 mT. This improvement was further investigated by Electrochemical Impedance Spectroscopy and Electrochemical Capacitance Spectroscopy studies. It is concluded that the enhanced electrochemical charge-transfer process of the Ni nanobrush electrode, with a magnetic field applied along the Ni nanowires axis, arises from a larger electroactive area. • A Ni nanobrush electrode is obtained by a single step electrodeposition route. • Nanobrush architecture consists of Ni NWs perpendicularly attached to a Ni layer. • The whole platform easy axis orientation is controlled by the brush shape and crystalline texture. • Catalytic activity towards redox probes Fe(CN) 6 −4/−3 and ethanol are evaluated. • A small magnetic field drastically reduces the nanobrush impedance.

Magnetic properties of Ni/BiFeO3 hybrid nanostructures

Next-generation spintronic applications, including magnetic nanosensors, energy-efficient data storage devices and magnetic memory devices, have obtained scientific and technological interest. One-dimensional (1D) core/shell nanomaterials are particularly interesting due to their promising anisotropic magnetic properties and exchange bias. Here, we investigate a versatile sol-gel and electrochemical deposition method and achieve Ni/BiFeO3 (Ni/BFO)'s controlled growth with tunable structure geometry. Significantly, BFO nanoshells on the pore walls and Ni nanowires inside the nanoshell are successfully deposited. Experimental and analytical observations show that the prepared Ni/BFO nanostructures have the ability to improve magnetic properties. This work presents a pathway for the controlled growth of hybrid nanostructures and provides a platform to study the tunable magnetic properties, suggesting their promise for practical applications.

Unveiling the Complex Magnetization Reversal Process in 3D Nickel Nanowire Networks

AbstractUnderstanding the interactions among magnetic nanostructures is one of the key factors to predict and control the advanced functionalities of 3D integrated magnetic nanostructures. In this work, the focus is on different interconnected Ni nanowires forming an intricate, but controlled, and ordered magnetic system: Ni 3D Nanowire Networks (3DNNs). These self‐ordered systems present striking anisotropic magnetic responses, depending on the interconnections’ position between nanowires. To understand their collective magnetic behavior, the magnetization reversal processes are studied within different Ni 3D Nanowire Networks compared to the 1D nanowire 1DNW array counterparts. The systems are characterized at different angles using first magnetization curves, hysteresis loops, and First Order Reversal Curves techniques, which provided information about the key features that enable macroscopic tuning of the magnetic properties of the 3D nanostructures. In addition, micromagnetic simulations endorse the experiments, providing accurate modeling of their magnetic behavior. The results reveal a plethora of magnetic interactions, neither evident nor intuitive, which are the main role players controlling the collective response of the system. The results pave the way for the design and realization of 3D novel metamaterials and devices based on the nucleation and propagation of ferromagnetic domain walls both in 3D self‐ordered systems and future nano‐lithographed devices.

Achieving Dendrite–free lithium Plating/Stripping from mixed Ion/Electron–Conducting scaffold Li2S@Ni NWs-NF for stable lithium metal anodes

Lithium metal is considered as an ideal anode material for the next generational high–energy–density energy storage system. However, due to nonuniform Li+ flux and electrons distribution, the further commercial application is limited by dendritic Li and infinite volume change during charging/discharging process. Herein, we designed a mixed ions/electrons conducting skeleton composited with Li2S protective layer and Ni nanowires on Ni foam (Li2S@Ni NWs-NF), towards realizing the dual–regulation of ions/electrons. The lithiophlic Li2S layer has high ionic conductivity, which not only can induce uniform Li nucleation along the nanowires but also regulate the Li+ flux. Meanwhile the Ni nanowires with high electronic conductivity can facilitate the electrons transport and lower local current density. Moreover, 3D skeleton provides space to mitigate volume change. Benefiting from the dual regulation of ions and electrons, an ultrahigh Coulombic efficiency of 98.7% for 200 cycles and a low overpotential with over 820 h long life–span could be achieved. Full cells coupled with LiFePO4 exhibit an excellent rate performance and capacity retention, illustrating the superiority of the Li2S@Ni NWs-NF as a mixed ion/electron conducting skeleton in alleviating the key problems of lithium mental anodes (LMAs) and provides a significant guidance for current collector design.

Long-range superconducting proximity effect in nickel nanowires

When a ferromagnet is placed in contact with a superconductor, owing to incompatible spin order, the Cooper pairs from the superconductor cannot survive more than one or two nanometers inside the ferromagnet. This is confirmed in the measurements of ferromagnetic nickel (Ni) nanowires contacted by superconducting niobium (Nb) leads. However, when a 3 nm thick copper oxide (CuO) buffer layer made by exposing an evaporated or a sputtered 3 nm Cu film to air, is inserted between the Nb electrodes and the Ni wire, the spatial extent of the superconducting proximity range is dramatically increased from 2 to a few tens of nanometers. Scanning transmission electron microscope study confirms the formation of a 3 nm thick CuO layer when an evaporated Cu film is exposed to air. Magnetization measurements of such a 3 nm CuO film on a SiO2/Si substrate and on Nb/SiO2/Si show clear evidence of ferromagnetism. One way to understand the long-range proximity effect in the Ni nanowire is that the CuO buffer layer with ferromagnetism facilitates the conversion of singlet superconductivity in Nb into triplet supercurrent along the Ni nanowires.

Measuring Cytoskeletal Mechanical Fluctuations and Rheology with Active Micropost Arrays.

The dynamics of the cellular actomyosin cytoskeleton are crucial to many aspects of cellular function. Here, we describe techniques that employ active micropost array detectors (AMPADs) to measure cytoskeletal rheology and mechanical force fluctuations. The AMPADS are arrays of flexible poly(dimethylsiloxane) (PDMS) microposts with magnetic nanowires embedded in a subset of microposts to enable actuation of those posts via an externally applied magnetic field. Techniques are described to track the magnetic microposts’ motion with nanometer precision at up to 100 video frames per second to measure the local cellular rheology at well‐defined positions. Application of these high‐precision tracking techniques to the full array of microposts in contact with a cell also enables mapping of the cytoskeletal mechanical fluctuation dynamics with high spatial and temporal resolution. This article describes (1) the fabrication of magnetic micropost arrays, (2) measurement protocols for both local rheology and cytoskeletal force fluctuation mapping, and (3) special‐purpose software routines to reduce and analyze these data. © 2022 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Fabrication of magnetic micropost arrays Basic Protocol 2: Data acquisition for cellular force fluctuations on non‐magnetic micropost arrays Basic Protocol 3: Data acquisition for local cellular rheology measurements with magnetic microposts Basic Protocol 4: Data reduction: determining microposts’ motion Basic Protocol 5: Data analysis: determining local rheology from magnetic microposts Basic Protocol 6: Data analysis for force fluctuation measurements Support Protocol 1: Fabrication of magnetic Ni nanowires by electrodeposition Support Protocol 2: Configuring Streampix for magnetic rheology measurements

Electrodeposited nickel–zinc alloy nanostructured electrodes for alkaline electrolyzer

Over the last decade, as a consequence of the global decarbonization process, the interest towards green hydrogen production has drastically increased. In particular a substantial research effort has focused on the efficient and affordable production of carbon-free hydrogen production processes. In this context, the development of more efficient electrolyzers with low-cost electrode/electrocatalyst materials can play a key role. This work, investigates the fabrication of electrodes of nickel-zinc alloys with nanowires morphology cathode for alkaline electrolyzers. Electrodes are obtained by the simple method of template electrosynthesis that is also inexpensive and easily scalable. Through the analysis of the morphological and chemical composition of nanowires, it was found that the nanowires composition is dependent on the concentration of two metals in the deposition solution. Electrocatalytic tests were performed in 30% w/w potassium hydroxide aqueous solution at room temperature. In order to study the electrodes stability, mid-term galvanostatic test was also carried out. All electrochemical tests show that nanowires with about 44.4% of zinc have the best performances. Particularly, at −50 mAcm−2, these electrodes have an overpotential 50 mV lower than pure Ni nanowire. NiZn nanowires show also a good stability over time without noticeable signs of performance decay.