Ni Tapes Research Articles

Laser crystallized sandwich-like MXene/Fe3O4/MXene thin film electrodes for flexible supercapacitors

For applications in portable electronics and miniaturized energy storage devices, MXene films derived from MXene inks can be provided as promising electrodes for thin film supercapacitors. Hence, to improve the areal capacitance of MXene films is necessary for pursuing high energy density. Introduction of transitional metal oxides (TMOs) layers into MXene electrodes obviously enhances the areal capacitance since of the extra pseudocapacitance induced by the surface/near surface redox reactions. The severe oxidation of MXene in combination with TMOs, however, hinders the effective improvements in capacitance. Laser crystallization process can effectively alleviate the oxidation of MXene when TMOs is prepared due to the high temperature localization and ultrafast reaction speed. Here, a sandwich-like MXene/Fe3O4/MXene film with a porous Fe3O4 layer is successfully prepared on a flexible Ni tape, showing an excellent electrochemical performance. In 1 M Li2SO4 aqueous electrolyte, the sandwich-like electrode demonstrates 46.4 mF cm−2 at the current density of 0.5 mA cm−2. The as-constructed symmetric all-solid-state device displays an energy density of 0.970 μWh cm−2 at a power density of 0.176 mW cm−2 along with a good cycling stability. This work opens up a new opportunity for modifying MXene films as electrodes for high-performance thin film supercapacitors.

Adhesion properties of CeO2 films produced from different precursors using sol-gel process

CeO2 films were deposited on Ni and Ag tapes by sol–gel process using nitrate, ammonium nitrate, colloidal, alkoxide, acetate, and oxalate based precursors and a detailed characterization of adhesion properties were performed in relation with structural features. The structural, microstructural and adhesion properties of the films heat-treated at 500 °C for 60 min in air were determined via XRD, ESEM and a mini tensile testing machine. The results showed that homogeneous films with cubic structure can be deposited on Ni and Ag tapes. The microstructure of the CeO2 films could also be tailored by altering precursor type, solvent, chelating agent and modifying liquid. The CeO2 joint samples with Ag tapes prepared from cerium(III)2,4 pentanedionate based solution exhibited the best adhesive properties because of polymeric sol and gel. The observed results in joint samples indicate a correlation between the failure types and the choice of solution from which CeO2 films prepared.

A systematic study in synthesis of CeO2 films on Ni tapes from different precursors using sol-gel process

A systematic study was comparatively performed in the synthesis of CeO2 films on Ni tapes from different precursors using sol-gel process. With this concept, CeO2 thin and thick films were deposited on Ni tapes by a reel-to-reel sol-gel dip-coating process using alkoxide- and nitrate-based precursors. The films were heat-treated at different temperatures for different times under 4%H2-Ar atmosphere. The structural and microstructural properties of these films were determined through XRD and ESEM. The structural and microstructural properties of these films depend on the preparation conditions. The films were found to be in the amorphous state until 300 °C or 400 °C. Upon raising heat-treatment temperature to nearly 500 °C, CeO2 polycrystalline films with a cubic structure were grown on Ni tape. It was determined that different anions and their concentrations strongly influenced the structure and microstructure of the films. Ce(NO3)3.6H2O and colloidal CeO2-based precursors showed better properties than the other ones as free cracks on the surface. It was determined that the annealing conditions for the texture structure were temperature (1150 °C), time (10 min), and specific media (4%H2-Ar flow). Depending on these conditions, the most pronounced texture was acquired in a thickness range of 100 and 300 nm in CeO2 films.

SmBa2Cu3O7−δ superconducting layer prepared on NiO buffer layer through fluorine-free chemical method

With energy shortage becoming increasingly severe, the application of high-temperature superconducting material is a considerable prospects, where economic, efficient and energy-saving preparation technology becoming the key factors for the large-scale applications of [Formula: see text] (REBCO) superconducting coated conductors. Currently, non-vacuum chemical solution deposition technique is an important way to reduce the cost of preparation of coated conductors. However, a randomly oriented NiO growth is an important problem for the non-vacuum chemical preparation of superconducting coated conductor. A simple and valid method is to prepare textured NiO film on the bare nickel (Ni) tape. In this paper, NiO films with [Formula: see text]-axis texture were prepared in air and in argon respectively by the surface oxidation epitaxial method. We obtained the smooth and densification NiO films. The layer of [Formula: see text] was fabricated on the NiO film via a fluorine-free chemistry method. The purpose of this paper is to provide a potential value of non-vacuum chemical solution deposition technique for preparation of REBCO superconducting coated conductors.

Preparation and properties of Bi6Fe2Ti3O18 thin films on metallic Ni tapes by chemical solution deposition

Ferroelectric Bi6Fe2Ti3O18 (BFTO) thin films were deposited on flexible metallic Ni (200) tapes by chemical solution deposition method. The effects of annealing temperature and La0.5Sr0.5TiO3 (LSTO) buffer layer on the microstructure, dielectric, leakage and ferroelectric properties have been studied. With increasing annealing temperature, the crystallite size increases while the dielectric constant, the leakage current density, the coercive field and the remnant polarization increase initially and then decrease. At low annealing temperature BFTO thin films on Ni tapes display flat surface without cracks, no NiO phase and good ferroelectric hysteresis loops. At high annealing temperature improved ferroelectric properties can be only observed in BFTO thin films on Ni tapes with a LSTO buffer layers. It will provide an instructive route to prepare and optimize the properties of BFTO thin films on metallic tapes by chemical solution deposition method.

The Influence of the Microstructure and Morphology of CeO 2 Buffer Layer on the Properties of YBCO Films PLD Grown on Ni Tape

YBa2Cu3O7−δ films were deposited on CeO2-buffered nickel substrates, with different buffer thickness. Full width at half maximum of rocking curve, Δω, of CeO2 and yttrium barium copper oxide (YBCO), as well as the critical temperature, T c, of YBCO were shown to be strongly dependent on buffer thickness. They behave similarly but not proportional to the buffer thickness increase. This and the fact that Δω vs. buffer thickness and T c vs. buffer thickness for YBCO behave similar with RMS roughness vs. thickness of CeO2 indicates that the surface peculiarity of buffers is responsible for YBCO properties. More precisely, the surface of CeO2 films prepared by the chemical solution route based on propionic acid is prone to agglomerate (de-wet) and the degree of agglomeration depends in an intricate way on buffer thickness. We showed that nor RMS roughness neither (00 l) texture degree can define alone the surface suitable for c-axis YBCO nucleation. The {111} faceted grains (even in the case of high (00 l) texture) and other defects generated by agglomeration supply a low fraction of (00 l) flat terminations of buffer that affect the nucleation of c-axis-oriented YBCO phase. Moreover, the thermal instability of the surface morphology of CeO2 buffers (further development of de-wetting process, {111} faceted grains, etc. during superconducting layer deposition) influence the quality of YBCO films.

Magnetoelectric properties of flexible BiFeO3/Ni tapes

We report ferroelectric (FE), ferromagnetic, and magnetoelectric (ME) properties of BiFeO3 films directly deposited on flexible magnetic Ni tapes. Without use of metal-oxide and/or noble metal buffer layer between the BiFeO3 and the Ni, both ferroelectric and magnetic properties of the film and the substrate are preserved. X-ray diffraction and transmission electron microscopy analyses confirm the formation of preferentially oriented (110) BiFeO3 film on Ni tapes. The BiFeO3 film has a saturation polarization and a piezoelectric d33 coefficient of 69 μC/cm2 and 52 pm/V, respectively. The BiFeO3/Ni tape shows a magnetoelectric coefficient of 3.5 mV/cm·Oe.

Rapid Deposition of Buffer Layers for YBCO Coated Conductors on Biaxially-Textured Ni Tapes

Epitaxial growth of CeO2 buffer layers on biaxially textured (001)Ni tapes was studied using pulsed laser deposition. Relationships between microstructure and deposition parameters were systematically studied in order to develop reliable long tape coating processes. It was found that orientation and texture of CeO2 buffer layers were sensitive to deposition parameters. X-ray diffraction analyses showed that CeO2 buffer layers had pure (001) orientation at 860 °C. Under optimized deposition conditions, highly (001) oriented CeO2 buffer layers have been achieved at a high deposition rate of 1.5 nm/s in-plane texture and out-plane texture of CeO2 buffer layers were 4.25 degrees and 5.85 degrees, respectively.

Numerical Investigation of Residual Stresses in YBCO/CeO2/YSZ/CeO2/Ni Architextured Materials for Coated Conductors

In this study, the stress analysis of YBCO/CeO2/YSZ/CeO2/Ni architextured materials under cryogenic conditions was carried out for coated conductor applications. YBCO/CeO2/YSZ/CeO2 multilayer films were fabricated on Ni tape substrate using reel-to-reel sol-gel and Pulse Laser Deposition (PLD) systems. The microstructural evolution of high temperature superconducting YBCO film and buffer layers with CeO2/YSZ/CeO2 configuration grown on textured Ni tape substrates were investigated by a Scanning Electron Microscope (SEM). SEM observations revealed that crack-free, pinhole-free, continuous superconducting film and buffer layers were obtained by solgel and PLD systems. The thermal distribution in the each layer was calculated using the classical lamination theory in the temperature range of 25 to -270°C in liquid helium media. The residual stresses occurred during the manufacturing are neglected therefore, all the residual stresses are assumed to be zero at 25°C. Different thermal expansion coefficients and modulus of elasticity bring about the thermal stresses in the layers.

Effect of substrate topography for YBa2 Cu3 O7-x coated conductors on the nucleation mechanism of buffer layer

The surface condition of substrate tape is an important factor to obtain epitaxial buffer layer on biaxially textured Ni tape for YBa2Cu3O7-x coated conductors. We prepare ceria films on Ni single crystal, biaxially textured Ni tape and sulfured Ni substrates by direct current magnetron sputtering. The results show that the ceria films prepared on Ni single crystal and sulfured Ni substrates each have a poor-textured grain structure. However, the ceria film fabricated on rolling assisted biaxially textured substrate (RABiTS) exhibits a good c-axis texture and desirable surface morphology. Reflection high-energy electron diffraction analysis indicates that the c(22) superstructure on the RABiTS Ni surface has a dramatic effect on the heteroepitaxial growth of oxide buffer layer.

Rare-earth mixed oxide thin films as 100% lattice match buffer layers for YBa 2Cu 3O 7−x coated conductors

Buffer layers with 100% lattice match with YBa 2Cu 3O 7 − δ (YBCO) were prepared from mixed rare-earth-oxides applying a simple sol–gel process and dip-coating method. Structural analysis of the sol–gel derived powder by X-ray diffraction revealed that the mixing parameter, which eliminates the lattice mismatch with YBCO, is x = 0.2382, 0.1852, 0.1252, 0.0906, 0.0793 and 0.0395 in (Eu 1 − x Ho x ) 2O 3, (Eu 1 − x Er x ) 2O 3, (Eu 1 − x Yb x ) 2O 3, (Gd 1 − x Ho x ) 2O 3, (Gd 1 − x Y x ) 2O 3 and (Gd 1 − x Yb x ) 2O 3, respectively. Microstructural investigations were carried out for Gd 1.819Ho 0.181O 3 films epitaxially grown on cube-textured Ni (100) substrates by sol–gel dip-coating process. X-ray diffraction of the buffer showed strong out-of-plane orientation on Ni tape. The (Gd 1 − x Ho x ) 2O 3 (222) pole figure indicated a single cube-on-cube textured structure. The omega and phi scans revealed good out-of-plane and in-plane alignments. The full-width at half-maximum values of omega and phi scan of (Gd 1 − x Ho x ) 2O 3 films was observed at 4.21° and 6.81°, respectively. Micrographs of the film obtained by using environmental scanning electron microscope and atomic force microscope revealed pinhole-free, crack-free, smooth and dense microstructures.

Preparation of NiO Buffer Layer by Direct Oxygenation of Ni Tape

Recently, Nickel-based alloys are widely used for textured substrates tapes. However, the deposition of oxide buffer layers on nickel tapes is required to stop the diffusion of nickel from the tape to superconducting layer and to improve the mismatch between the substrate and superconducting film. Biaxially textured NiO buffer layer is easily formed on cubic textured nickel tape by the technique called surface oxidation epitaxy. In this work, we developed a direct oxygenating method to make the NiO buffer layer on nickel tape. The nickel tape was directly oxygenated in different atmospheres. It is found that in inert atmosphere, a high quality NiO layer can be formed on the surface of the tape. The oxygenating conditions, including atmospheres and temperatures, and their influence on the structure of the NiO buffer layer, were studied in detail and discussed.

Characterization of Buffer Layers on Ni-based Substrates for YBCO Superconductors

Metal oxide buffer layers provide a continuous, smooth textured and chemically inert surface for growth of the YBCO (YBa2Cu307-x) film and prevent metal diffusion from the substrate into the superconductor. Ce02, Gd203 and EU203 buffer layers were grown on metallic Ni substrates using a sol-gel method by using metal 2,4-pentanedionate and acetate precursors. The films were annealed at 1150°C under 4%H2-Ar gas mixture. Textured, crack free and continuous buffer layers were obtained through the sol-gel technique. Prior to the coating process, solution characterization was performed by turbidimeter, pH meter, contact angle goniometer and rheometer. Heat treatment profiles were determined by using DTA-TG and FTIR. The coated layers were characterized by means of XRD, SEM-EDS, AFM and a scratch tester. As a result, textured growth of Ce02, EU203 and Gd203 thin films on textured Ni tapes by the sol-gel dip coating process were successfully performed.

Fast Growth Processes of Buffer Layers for YBCO Coated Conductors on Biaxially-Textured Ni Tapes

Epitaxial growth of CeO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> buffer layers on biaxially textured (001) Ni tapes was studied using reel-to-reel pulsed laser deposition. Relationship between microstructure and deposition parameters was systematically studied in order to develop reliable long tape coating processes. Prior to buffer layer deposition, Ni tapes were in situ annealed in forming gas (97% argon + 3% hydrogen) under various pressures and tape speeds to accelerate reel-to-reel annealing processes. It was found that orientation and texture of CeO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> buffer layers were sensitive to deposition parameters. X-ray diffraction analyses showed that CeO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> buffer layers had pure (001) orientation at forming gas pressure of 5 mTorr and 700degC. Under optimized deposition conditions, highly (001) oriented CeO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> buffer layers have been achieved at a high tape speed of 20-50 m/h. In-lane texture of CeO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> buffer layers was 7 degree which was comparable to the value of Ni tapes.

Effect of Temperature and Film Thickness on Residual Stress and Texture of ${\rm Re}_{2}{\rm O}_{3}$ Buffer Layers for YBCO Coated Conductor

Re2O3 (Re = Er, Gd, Ho, Y and Yb) was prepared by sol-gel synthesis using metal-organic precursors. Residual stress and microstructure in the Re2O3 buffer layers were investigated as a function of temperature and film thickness. Textured Re2O3 buffer layers were grown on biaxially textured-Ni (100) substrates using chemical solution deposition. Films were annealed at 1150degC under a flowing 4% H2-Ar gas. X-ray diffraction of the buffers showed strong out-of-plane orientation on Ni tape. Residual stress in various thicknesses of buffer layers was calculated. The surface morphologies and microstructure of all samples were characterized using SEM and AFM.

Novel water based cerium acetate precursor solution for the deposition of epitaxial cerium oxide films as HTSC buffers

A novel water based precursor solution using ethylenediaminetetraacetic acid (H4EDTA) as a complexant and acetic acid and ethylenediamine (EDA) as additional components to obtain CeO2 buffer layers on Ni (5%W) tapes is described in detail. The influence of complexation behavior in the formation of transparent and homogenous sols and gels by the combination of cerium acetate, acetic acid and H4EDTA has been studied. The optimal growth conditions for cerium oxide were Ar-5% H2 gas processing atmosphere, solution concentration levels of 0.2–0.4 M, a dwell time of 60 min at 900 °C and 5–30 min at 1,050 °C. X-ray diffraction, SEM, spectroscopic ellipsometry and pole figures were used to characterize the CeO2 films. Highly textured CeO2 layers were obtained.

INTEGRATION OF FERROELECTRIC BaTiO3 THIN FILMS DIRECTLY ON NI AND TI METALLIC TAPES FOR STRUCTURAL HEALTH MONITORING SYSTEMS AND ENERGY HARVEST APPLICATIONS

ABSTRACT Ferroelectric BaTiO3 thin films were fabricated directly on various metallic substrate materials such as Ni and Ti by using the pulsed laser for the development of structural health monitoring systems and energy harvest applications. Microstructure studies from x-ray diffraction and electron microscopy indicate that the as-grown BaTiO3 thin films have pure BaTiO3 crystal phase. The TEM studies indicate that the BaTiO3 films are composed of crystalline assemblage of nanopillars with average cross sections from 100 nm to 200 nm and can be directly integrated on the Ni tapes without the formation of NiO interlayer suggesting that this system can be developed for super-capacitor devices. The BaTiO3films have good interface structures and strong adhesion with respect to Ni and Ti substrates. Dielectric measurements have shown the hysteresis loop at room temperature in the film with a large remanent polarization, indicating that the ferroelectric domains have been created in the as-deposited BTO films. The successful integration of ferroelectric thin films directly on metallic materials has promised for the development of the structural health monitoring systems and energy harvest devices.

Processing and Characterization of Ni Base Coated Superconductor Substrate Tapes With Layered Architecture

Ni/Ni-5 at.%Mo and Ni/Ni-5 at.%Mo/Ni multilayer tapes were prepared from elemental powders by a powder metallurgy route for coated superconductor substrate applications. The development of cube texture ({001}(100)) following heavy cold rolling ( ~95%) and annealing has been studied in the Ni side(s) of these multilayer tapes and compared to a nonalloyed Ni tape. Although the deformation textures in the Ni side(s) of these multilayer tapes appear quite similar to that of the nonalloyed Ni tape cold rolled to a similar deformation level, the volume fraction of the cube grains in the Ni side(s) of the multilayer tapes following annealing shows marked improvement as compared to the nonalloyed Ni tape after different annealing treatments. X-ray area mapping from typical cross-sectional areas of the multilayer compacts in the sintered condition reveals significant diffusion of the alloying element Mo from the alloy side(s) to the Ni side. These facts amply corroborate the earlier observation on the beneficial role of Mo on the development of cube texture in Ni. The yield strength of the annealed multilayer tapes shows marked improvement over nonalloyed Ni tapes.

Textured nickel tapes prepared from commercially available material

Abstract Textured Ni tapes were fabricated from commercially available nickel pellets (98.5% Ni). Ingots produced by a melt process were cold rolled to 150–400 μm thick tapes. Texturing was achieved by annealing in a reducing atmosphere (Ar + 6.5% v/v H2). Sharp cubic biaxial textured Ni tapes were obtained by thermal treatment at 1000°C for 2 hours in a reducing atmosphere. The tapes were characterized by scanning electron microscopy, X-ray diffraction and by electron backscattering diffraction. The tensile strength, the thermal expansion behavior and the Vickers hardness for the cold rolled tapes and for the heat-treated tapes were measured.

Modeling Thermal Process in a Resistive Element of a Fault Current Limiter

The thermal regime of the Ni tape immersed into liquid nitrogen and heated up due to Joule losses generated by a step-like direct current is studied experimentally and theoretically. The temporal dependence of the temperature rise in Ni tape is measured. An adiabatic approach is shown to give a conservative result. According to our results, taking into account the heat transfer by thermal conduction into liquid nitrogen is necessary. This circumstance allows one to reduce a significantly necessary amount of high-temperature-superconductor material for the superconducting part of a resistive fault current limiter.