Nickel Composite Films Research Articles

Fabrication of Electroplated Nickel Composite Films Using Cellulose Nanofibers Introduced with Carboxy Groups as Co-Deposited Materials

In this study, the fabrication of nickel (Ni)-cellulose nanofiber (CNF) composite electroplating films was attempted using sodium carboxymethyl cellulose (CMC) and 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO)-oxidized CNF as CNF introduced with carboxy groups. As a result, co-deposition was confirmed for both CNFs, and the former showed 82% improvement in surface Vickers hardness compared to the plated film deposited from a conventional Watts bath without CNF. Although the latter showed slightly inferior 71% improvement, the surface roughness measurement showed a smoother surface than that of the plated copper material C1100. On the other hand, the film with CMC had a rough surface. The image analysis showed that the distance between co-deposited CNF on the surface of the plated film was 40% shorter on the specimen with TEMPO CNF than CMC, indicating that a fine dispersion was obtained. In addition, a co-deposition model was proposed in which Ni is deposited from the chelate complex formed between the carboxylate of CNF and Ni ions. CNF is fixed to the plated film surface by Ni deposition and the simultaneous bond of hydrogen ions to the carboxylate, resulting in a return to the carboxy group.

Influence of annealing process on surface micromorphology of carbon–nickel composite thin films

In this research, we investigated carbon–nickel composite films prepared by RF-magnetron co-sputtering on quartz substrates using a multi-component target (10 cm in diameter) consisting of pure graphite (99.99%) and strips of pure nickel (approx. 2 cm2 in size) attached to the graphite race track, that corresponds to around 2.5% in area. The substrates were ultrasonically cleaned in acetone bath for 20 min and dried in hot air flow prior to deposition process. The films were grown at room temperature in a deposition chamber evacuated to a base pressure 1 × 10−3 N/m2 and then the constant Argon working pressure of 4 N/m2 was settled and maintained by throttle valve. Deposition was done in constant RF power regime 400 W. The films were deposited for 600 s and then annealed for 2 h in a furnace at the temperature: 300, 500, 800 and 1000 °C under ambient atmospheric pressure.

Porosity Evaluation and the Power Spectral Densities Analyses of Carbon–Nickel Composite Films Annealed at Different Temperatures

The densification and the fractal dimensions of carbon–nickel films annealed at different temperatures 300, 500, 800, and 1000°C with emphasis on porosity evaluation are investigated. For this purpose, the refractive index of films is determined from transmittance spectra. Three different regimes are identified, T < 500°C, 500°C < T < 800°C and T > 800°C. The Rutherford backscattering spectra show that with increasing the annealing temperature, the concentration of nickel atoms into films decreases. It is shown that the effect of annealing temperatures for increasing films densification at T < 500°C and T > 800°C is greater than the effect of nickel concentrations. It is observed that the effect of decreasing nickel atoms into films at 500°C < T < 800°C strongly causes improving porosity and decreasing densification. The fractal dimensions of carbon–nickel films annealed from 300 to 500°C are increased, while from 500 to 1000°C these characteristics are decreased. It can be seen that at 800°C, films have maximum values of porosity and roughness.

Multiphonon hopping conduction in carbon–nickel composite films at different deposition time

In this work, the electrical properties of carbon–nickel composite films deposited at different time (50–600 s) were investigated. The films were grown by radio frequency magnetron sputtering on glass substrates at room temperature. The electrical conductivity of the films was investigated in the temperature range of 15–500 K. The conductivity data in the temperature range of 400–500 K show the extended state conduction mechanism, while the multiphonon hopping (MPH) conduction is found to dominate the electrical transport in the temperature range of 150–300 K. The films deposited at 180 s have the maximum conductivity. The conductivity at T < 60 K could be described in terms of variable range hopping (VRH) conduction. The localized state density around Fermi level (N(EF)) at low temperature for the films deposited at 180 s has the minimum value of about 4.02 × 1021 cm−3·eV−1. The average hopping distance (Rhop) for the films deposited at 180 s has the maximum value of about 3.51 × 10−7 cm.

Study of electric susceptibility, electrical resistivity and energy loss functions of carbon–nickel composite films at different annealing temperatures

In this work, the optical and electrical properties of carbon–nickel films annealed at different temperatures (300–1000 °C) were investigated. The obtained data of the refractive index n using the Swanepoel’s method can be analyzed to obtain the high-frequency dielectric constant which describes the free carriers and the lattice vibration modes of dispersion. The lattice dielectric constant ϵL and the plasma frequency ωp at 500 °C have maximum values 4.95 and 40.02 × 106 Hz, respectively. The free carrier electric susceptibility measurements in wavelength range (300–1000 nm) are discussed according to the Spitzer–Fan model. It is shown that the electric susceptibility at 500 °C has maximum value and with increasing wavelength it increases. It is also shown that the waste of electrical energy as heat at 500 °C has maximum value and with increasing wavelength it increases. It is found that energy loss by the free charge carriers when traversing the bulk and surface of films at 800 °C has a minimum value and it is approximately constant with wavelength. It is shown that optical properties were consistent with electrical properties of films annealed at different temperatures in temperature range (15–500 K).

Surface plasmon resonance and electrical properties of RF: magnetron sputtered carbon–nickel composite films at different annealing temperatures

In this work, the optical absorption spectra of carbon–nickel films annealed at different temperatures (300–1000 °C) with a special emphasis on the surface plasmon resonance (SPR) were investigated. The films were grown on quartz substrates by radio-frequency (RF) magnetron co-sputtering at room temperature with a deposition time of 600 s. The optical absorption peaks due to the SPR of Ni particle are observed in the wavelength range of 300–330 nm. With annealing temperature increasing up to 500 °C due to the increase in Ni particle size, the intensity of the SPR peaks increases, but weakens with annealing temperature increasing over 500 °C. The Ni nanoparticle size, the dielectric function of carbon matrix (e m) and the plasma frequency of the free electrons (ω p) at 500 °C have the maximum values of 21.63 nm, 0.471 and 5.26 × 1015 s−1, respectively. The absorption peak shows a redshift trend up to 500 °C and then turn to blueshift with annealing temperature increasing over 500 °C. These observations are in a good agreement with the electrical measurements in temperature range of 15–520 K and the Maxwell–Garnett (M–G) effective medium theory (EMT).

Study of Structural, Electrical and Magnetic Properties of RF-Magnetron Sputtered Carbon–Nickel Composite Films at Different Deposition Rate

In this work, the magnetic properties and the electrical conductivity of carbon–nickel composite films deposited at different deposition times 50–600 s were investigated. The films were grown by radio frequency magnetron co-sputtering on glass substrates at room temperature. The nickel concentration in the films are effected by changing of the deposition rate and measured by energy dispersive X-ray studies. Values of coercive field were measured under both increasing and decreasing applied magnetic field. It is shown that the coercive field strongly dependent on both the nickel concentration and nickel nanoparticle size and at 180 s films has maximum value 68.04 (Oe). The difference in the coercive fields increased for films deposited from 50 to 180 s and then decreased for films deposited at 600 s. The ID/IG ratio of Raman spectra would indicate the presence of higher sp2 bonded carbon in the films deposited at 180 s. For entire temperature range (15–500 K), the electrical conductivity of films deposited up to 180 s increases and then from 180 to 600 s it decreases. These observations are in a good agreement with the field emission scanning electronic microscopy (FESEM) images.

Effect of annealing temperature on the optical loss and the optical constants of RF-magnetron sputtered carbon — nickel composite films

In this work, the optical properties of carbon — nickel films annealed at different temperatures (300–1000 °C) were investigated. The films were grown on quartz substrates by radio frequency magnetron co-sputtering at room temperature with a deposition time of 600 second. The optical transmittance spectra in the wavelength range 300–1000 nm were used to compute the refractive index by using the Swanepoel’s method. The films annealed at 500 °C showed considerable optical loss due to optical absorption by nickel atoms and to scattering caused by surface roughness. However, the film annealed at 800 °C had a very small optical loss in spite of the high surface roughness. The dispersion curves of the refractive indices of the films had anomalous dispersion in the absorption region and normal dispersion in the transparent region. The dissipation rate of the electromagnetic wave at 500 °C was shown to have maximum value.

Coloration by Zinc–Nickel Composite Films Electrodeposited from a Chloride Solution

Coloration by Zinc–Nickel Composite Films Electrodeposited from a Chloride Solution

Influence of Deposition Rate on Optical Properties of RF-Magnetron Sputtered Carbon–Nickel Composite Films Deposited at Different Deposition Times

In this work, the optical properties of carbon–nickel films deposited at different deposition times from 50 to 600 sec were investigated. Reflectance measurements in wavelength range 300–1000 nm were used to compute the refractive index and optical dispersion parameters according to Wemple and DiDomenico single oscillator model (WDD). Dispersion curves of the refractive index of films show anomalous dispersion in absorption region and normal dispersion in transparent region. It is shown that dissipative rate of the electromagnetic wave at 180 sec has a maximum value. It is also shown that at 180 sec films become more disordered.

Cobalt–nickel composite films synthesized by chemical bath deposition method as an electrode material for supercapacitors

Cobalt–nickel (Co–Ni) composite thin films were fabricated on copper substrates using a simple chemical bath deposition route in an ammonia-complexed solution containing cobalt chloride and nickel chloride. The structural and morphological properties of the film confirmed that the chemically deposited Co–Ni composites formed in the hydroxide phase and were well covered with irregular shaped nano-platelets. The chemically deposited Co–Ni composite electrode exhibited a maximum specific capacitance of 324 F/g, which was much larger than that of the pristine components. The cyclic voltammetry and charge–discharge test showed that the capacitance of the chemically deposited Co–Ni composite electrode mainly consisted of a pseudocapacitance.

X-ray photoelectron spectroscopic study of magnetron sputtered carbon–nickel composite films

Carbon–nickel films were deposited by direct current magnetron sputtering in argon plasma at temperatures between 25 and 800 °C. The films have a composite structure, consisting of a nanocrystalline dispersed phase embedded in an amorphous carbon matrix as revealed by high resolution transmission electron microscopy. Based on selected area electron diffraction, the crystalline phase was assigned to hexagonal nickel carbide (Ni 3C) for films grown below 400 °C and to face centered cubic nickel for those prepared above 400 °C. X-ray photoelectron spectroscopic studies verify these results. In films deposited below 400 °C the carbon 1s spectral range contains two low binding energy components at 283.2 and at 281.5 eV (± 0.2 eV). While the peak at 281.5 eV corresponds to the carbidic environment, the component at 283.2 eV, existing also in high temperature samples, is assigned to carbon atoms constituting the interface between the carbon matrix and the Ni 3C or Ni crystallites.

Raman spectroscopic study of magnetron sputtered carbon–nickel and carbon nitride–nickel composite films: The effect of nickel on the atomic structure of the C/CN x matrix

Carbon (C), carbon nitride (CN x ), C–nickel and CN x –nickel films were deposited by direct current magnetron sputtering onto oxidized (100) Si substrates, at 25, 200, and 500 °C growth temperatures. Raman spectroscopy was used to examine the bonding structure of C and CN x , and to investigate the effect of the Ni dispersed phase on the atomic structure of the C or CN x matrix of composite films. The atomic structure of the matrix is different for the C–Ni and for the CN x –Ni films. In the C and C–Ni films graphene-like sp 2-ordering, in the CN x and CN x –Ni films fullerene-like sp 2-ordering was found. For both types of composite films, the presence of the dispersed phase enhances the sp 2-ordering of the matrix.

Novel Semiconducting Phase of Amorphous Carbon Nickel Composite Films

AbstractA homogeneously mixed phase of carbon and 10% nickel yielding amorphous carbon-nickel composite (a-C-Ni) films is prepared by an excimer UV pulsed laser ablation. Conductivity study of these films shows a nearly activated conduction. Also a saturation of conductivity below a temperature of 25 K explains the presence of an additional density of states at the Fermi level in these samples. Our experiments demonstrate a very different behaviour of electronic properties of these novel materials compared to undoped diamond-like carbon (DLC) films, which was directly confirmed using valence band spectroscopy.

Al 2O 3-nanoparticle distribution in plated nickel composite films

Electrolytic codeposition is a well-known and suitable process for the production of particle compound materials. Dispersion strengthened Ni-Films were obtained by codeposition of laser generated Al 2O 3-particles having a median particle diameter of 14 nm. The codeposition was achieved by adding the Al 2O 3-nanopowders to a typical sulfamate-bath before electroplating nickel on copper substrates. The deposited nickel compound films were separated from the substrate and prepared for TEM investigations by electrolytic jet polishing and ion milling. The size distribution of the nanoparticles in the films was determined and correlated with the size distribution of the employed nanopowder. As-plated n- Al 2O 3 Ni -specimens were also annealed at 850 °C for 20 h followed by measurements of the microhardness at ambient temperatures.