Papers by Keyword: NiO

Abstract: This study considers the growth characteristics of nickel oxide NiO films using DC magnetron sputtering. The hysteresis transition process between sputtering from poisoned and clean Ni target as a function of discharge power was determined. The structure, atomic composition, and optical and electrical properties of NiO films for two modes of sputtering (with low and high discharge power, respectively) have been investigated. It is demonstrated that sputtering parameters have a fundamental effect on both the formation of structure and atomic composition and on the trend of their modification using temperature annealing. The results obtained for each of the sputtering modes can be applied to the development of devices based on catalytic reactions as well as on their semiconductor properties.

Abstract: Aluminum-doped NiO thin films were generated on glass substrates by dip coating at different temperatures (400 to 500 °C) using 0.05 M of the precursor nickel acetate. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to investigate the structural and morphological aspects of the films. UV-visible spectroscopy was utilized to assess the optical properties of the films, and the energy band gap was confirmed to be 3.42,3.6, and 3.8 eV for as-prepared and thin films, respectively. Photoluminescence (PL) measurements were used to investigate electronic faults. The XRD lines of the transferred Al-doped NiO were strengthened due to the fact the film's temperature content increased due to the improved crystalline structure. This research article focuses on the optical properties and morphologies of thin films which have been deposited. Crystalline proportions of the thin films that were deposited were determined using the Debye-Scherer formula. The outcomes were computed after taking measurements of absorbance (A), transmittance and Band Gap.

Abstract: Nickel Oxide nanofibers were successfully prepared by electrospinning with a precursor mixture of Ni acetate/polyvinylpyrrolidone (PVP), followed by calcination treatment of the electrospun composite nanofibers. The parameter of solution and effect of applied voltage to the morphology of nanofibers were studied. Both Ni acetate/PVP and NiO NFs, nanofibers were characterized by FESEM and XRD. The results found that the nanofibers form with smooth surface without beads and the calcination temperature was at 500°C to produce NiO nanofibers.

Abstract: The technology of natural gas adsorbed can be called Adsorbed Natural Gas (ANG) technology use porous adsorbents to adsorb natural gas. The material is activated carbon (AC), which has a large specific surface area. Activated carbon made from cassava peel waste because of abundance as agricultural waste in Indonesia. Cassava peel has a high cellulose and lignin content. Cassava peel through the carbonization process with furnace temperature 500 ° C in vacuum condition for 1.5 hours. Then, chemical activation with a different activator agent KOH and NaOH by mass ration (3:1). After that, physic activation with N₂ and CO₂ gas of 150 mL/minute using temperature muffle furnace 750 ° C. Product of physic activation modified using (Ni (NO₃)₂). Characterization of activated carbon performed with iodine test, SEM, EDX, adsorption, and desorption testers. The best of activated carbon is activated carbon impregnated KOH and with physic activation at 750 ° C, which has 612 mg / g of iodine number. Then, after activated carbon modified using (Ni (NO₃)₂) has the best performance with 1% NiO, has 662 mg / g of iodine number, and 657 m2 / g of S_BET. Then, activated carbon through adsorption and desorption test by ANG technology has 0.02928 kg/kg of adsorption capacity and 39.17% of desorption percent.

Abstract: Acetone is a main respiratory marker for diabetic patients. In this paper, P-type NiO nanofibers were prepared by electrospinning and used for the detection of acetone gas. NiO nanofibers were characterized by SEM and XRD. The uniform NiO nanofibers with face-centered cubic structure was obtained. The working temperature of NiO nanofibers was optimized, and the optimal operating temperature is 220°C. The response-recovery curve was tested, and the response and recovery time is 24.6 s and 610 s respectively. The response to different concentrations of acetone was also analyzed, and the detection limit was 100 ppb. These results show that NiO nanofibers based on electrospinning have potential applications in the respiratory testing of diabetes.

Abstract: We have prepared nondoped and Cu-doped NiO thin films by sol-gel method on SiO2 substrate using nickel acetate and copper acetate as precursors. Thin films of NiO were formed by thermal annealing of gel films at 500 - 900°C for 10 h in air. X-ray diffraction (XRD) peaks of NiO have been observed at higher annealing temperature than 500°C, and intensity of the peaks increased with annealing temperature until 800°C. On the other hand, the dependency of XRD signal intensity on annealing temperature becomes less significant by Cu-doping. Nondoped NiO films show high transparency at lower annealing temperatures than 800°C. The result means that the film with high crystalline volume ratio is not consistent with the films with high transparency. Cu-doping decreases the transmittance of the films with low crystalline volume ratio. It is considered that the doped Cu atoms exist in amorphous fraction make the transmittance lower. Conductivity of the films is increased with Cu-doping only in the films annealed at 500 - 700°C. The highest conductivity obtained in the Cu-doped film is around 10-6 W-1cm-1 at 600°C. On the other hand, the Cu-doped films show similar conductivity to nondoped films at high annealing temperature, 800 or 900°C.

Abstract: Generally, traditional low infrared coatings based on metallic pigments cannot have low lightness, low infrared emissivity and low radar reflectivity simultaneously. Herein, we used a simple and efficient method to synthesize magnetic Al/NiO composite pigments which possessed all these attributes to a degree. The results indicated that the covering area of NiO on the aluminum flake could be tuned by the addition amount of NiCO₃ and the reaction temperature of hot-flowing, both of which played a key role on the VIS/IR spectral reflectance and magnetic properties. The magnetic Al/NiO composite pigments with low lightness and low infrared emissivity could be obtained at 130 °C for 24 h in hot flowing liquid. The lightness L* could be decreased to 75.94, however the infrared emissivity (8-14 μm) was also low to 0.421. Compared with the single aluminum flakes, the Al/NiO magnetic composite pigments presented stronger magnetic properties. Therefore, the Al/NiO magnetic composite pigments offered a new choice for the pigments of multispectral stealth coating.

Abstract: NiO/BiFeO₃ thin film has been deposited on Pt/Ti/SiO₂/Si substrate by sol-gel method. The structure of thin film is analyzed by X-ray diffraction, and the result of X-ray diffraction shows that a perovskite crystal structure can be well-grown on Pt/Ti/SiO₂/Si substrate. In addition, the surface morphology is characterized by a scanning probe microscope, and the image of scanning probe microscope indicates a good crystalline quality of NiO/BFO thin film. Moreover, the current-voltage properties are also measured by a semiconductor characterization system, and the stable and reproducible nonvolatile resistive switching characteristic for the memory application have been clearly observed in Pt/NiO/BiFeO₃/Pt structure, which could be attributed to the formation and rupture of filament localized in NiO thin layer.

Abstract: The objectives of this work are to prepare and to study some properties of zinc bismuth borate glasses containing NiO in chemical formula 10ZnO : 30Bi₂O₃ : (60-x)B₂O₃ : xNiO, with x is the concentration of NiO, ranges from 0.00 to 0.05 mol%. The results found that the density of glasses increase with increasing of NiO concentration, whereas the molar volumes decrease. Absorption spectra were performed using UV-VIS-NIR spectrophotometer in the region of ultraviolet to near infrared, the absorption peak was not found. Moreover, the color in CIE L^*a^*b^* of all glass samples were also investigated.

Abstract: Sr - doped NiO ceramic was prepared using solid state method. The calcination temperature used at 950 oC for 4 hours and the sintering temperatures was varied from 1100 to 1300 oC for 3 hours. The results depict the microstructures increasing in grains size (1-8 μm) by increase of sintering temperatures. The density and porosity testing support the result of microstructures analysis. The larger grains size induced the increase in density and lower in porosity. The dielectric properties is observed in a wide frequency range of (1 - 1 000 MHz). The increase of dielectric constant is associated with the decrease of dielectric loss. The optimum sintering temperature was obtained at 1200 oC depict the grain size range (1 - 2 μm) with highest dielectric constant (1.61 x 103) and lowest dielectric loss (1.15) at 1MHz.