Papers by Keyword: CoO

Abstract: Co/Cr co-doped in soda lime silicate (SLS) glasses were prepared by using normal melt quenching technique. The current composition was prepared based on the proposed ratio: (64.9-x)SiO₂: 10CaO: 25Na₂O: 0.1CuO: xCoO where x=0.00, 0.01, 0.02, 0.03, 0.04 and 0.05 mol% were prepared at 1200°C for 3 h, and annealed at 500 °C for 3 h. The physical and optical properties of Co/Cr co-doped in SLS glasses were investigated such as density, molar volume, refractive index and optical absorption were discussed and measured. The optical absorption spectrum of Co/Cr co-doped in SLS glasses measured at room temperature in the wavelength region 200–1100 nm were presented.

Abstract: The Co element was used during the first operation of high temperature reactor (HTR) reactor to distinguish low-enrichment and high-enrichment fuel elements. In this paper the YSZ/CoO ceramic tracer microspheres with YSZ coating were prepared. The design size of the microspheres were about 750μm. The YSZ shell thickness were 100 μm, the mean nuclear roundness were ≤1.03 and the density were ≥5.50g/cm³. Morphology, microstructure and element composition of the core-shell microspheres were characterized by stereo microscope, scanning electron microscopy, x-ray spectrometers etc. The results of both line scan and spot scan of X-ray spectrometer show that dense YSZ shell can efficiently prevent Co element in YSZ/CoO core from diffusing into the YSZ shell at high temperature.

Abstract: In this work, effects of CoO on silicoborate glasses have been investigated. Glasses were prepared in formula (53-x)B₂O₃:11SiO₂:32SrO:1Bi₂O₃:1TiO₂: xCoO (where x is 0.00, 0.01, 0.02, 0.03, 0.04 and 0.05 mol%). The results show that, the density and refractive index were increased with increasing of CoO concentration. The optical absorption spectra were measured by UV-Visible Spectrophotometer and show peaks correspond with Co²⁺ in glass matrices at a wavelength of around 511 584 and 649 nm for all glass samples.

Abstract: Physical and optical properties of mixed Mn-Co ions in soda lime silicate glasses were measured and calculated. The results show that, the densities increased with the increasing of CoO content. This indicates that increasing the molecular weight of oxide ions used in the glass was due to the replacing SiO₂ by CoO. The refractive indices were increased with increasing of CoO concentration. The absorption peaks of CoO doped glasses occurred at the wavelength around 511, 584 and 649 nm which are assigned to ⁴A₂(F) ® ²A₁(G), ⁴A₂(F) ® ⁴T₁(P) and ⁴A₂(F) ® ²E(G) transition, respectively.

Abstract: In commercial CMP tools, slurry is applied near the pad center. As the pad rotates, more than 95% of the fresh slurry flows directly off the surface due to bow wave formation and inertial forces without ever entering the pad-wafer interface, resulting in low slurry utilization [1]. Furthermore, some slurry that manages to go under the wafer stays on the pad, mixes with fresh slurry and re-enters the pad-wafer interface. This used slurry contains reaction products, foam and pad debris (due to pad conditioning) that cause wafer-level defects [2]. Such defect-causing by-products keep recirculating on the pad during polishing and accumulate near the retaining ring over time. Also, since large amounts of DI water are used between wafer polishes to rinse off the debris and reaction products, appreciable amounts of water may stay on the pad and inside the grooves. When fresh slurry is introduced to polish the next wafer, it mixes with the residual water and is diluted, resulting in lower material removal. As such, the current slurry application method does not provide efficient slurry utilization and leaves significant room for improving defect levels. Moreover, the constant sweeping of the conditioner arm during in-situ conditioning results in uneven slurry distribution and introduces additional challenges when it comes to carrier multi-zone pressure control for reduced within-wafer removal rate non-uniformity.

Abstract: A series of MO/ SnO₂ (MO=MnO₂, and CoO) core-hell nanocomposites were synthesized by a combined layer-by-layer technique and hydrothermal method. The results showed that SnO₂ or CoO loading enhanced the electron storage ability. When loading 3.0 wt% MnO₂ and 5.0 wt% CoO on SnO₂ nanotubes, after TiO₂ coating electrode was irradiated under UV irradiation for 1 h, the self-discharging time of the MnO₂/SnO₂ and MnO₂/SnO₂ core-hell nanocomposites electrodes was more than 7.5 h and 7.7 h, respectively. In addition, the as-synthesized MO/ SnO₂ core-hell nanocomposites coatings exhibited good photocathodic protection property for metals.

Abstract: In the present study, CoO, which is hard to synthesize because of the chemical activity of cobalt metal, and the popular Co₃O₄ have been successfully controlled produced by a salt-assisted combustion method (SACM), in which Co(NO₃)₂•6H₂O, polyethylene glycol (PEG2000) were chosen as oxidant and fuel respectively. The CoO and Co₃O₄ nanoparticles were investigated by high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), x-ray diffraction (XRD), simultaneous thermogravimetric and differential thermal analysis (TG-DTA) and N₂ adsorption. It is found that the pure CoO were obtained whatever adjusting the weight ratio of Co(NO₃)₂•6H₂O and PEG2000 in the absence of inert salt. While, well-dispersed Co3O4 nanoparticles with a high specific surface area were successfully obtained with the introduction of NaCl or KCl in the system, which results from the fact that the introduction of inert inorganic salt as a agglomeration inhibitor into the redox mixture precursor led to the breakup of fractal nanocrystallite agglomerates. A mechanism was proposed to illustrate the possible formation processes and the role of the inert inorganic salt.

Abstract: In this paper, p-n coupled photocatalyst CoO/CdS/TiO₂ was prepared by method of impregnation. The structure and optical properties of CdS/TiO2 and CoO/CdS/TiO₂ were characterized by XRD, SEM, BET and UV–vis DRS. The photocatalytic activities of the photocatalysts were evaluated by photocatalytic degradation of methyl orange, and the effect of photocorrosion of CdS in CoO/CdS/TiO₂ was investigated by analyzing the cadmium concentration in the supernate collected after photocatalytic reactions. The results showed that p-n coupled photocatalyst CoO/CdS/TiO₂ not only showed higher efficiency in degradation of methyl orange than CdS/TiO₂, but also exhibited resistance against cadmium leakage under light irradiation. The mechanism of the photocorrosion-delaying by p–n junction was also discussed.

Abstract: CoO was usually added to the positive electrodes of MH/Ni batteries as the conductive agent. In this paper, well crystallized multi-walled carbon nanotubes (CNTs) with diameter about 10 nm were added to the positive electrodes of MH/Ni batteries together with CoO. During the process of transformation from CoO to CoOOH, a complex conductive network was created with CNTs as the frame. Because of the high conductivity and the excellent tension characteristics of CNTs, the charge-transfer capability of the electrode was improved and the integrality of the complex conductive network was enhanced. The electrochemical measurements indicated that the impedance of the electrode with CNT-CoO complex conductive agent was lessened compared to the electrode with simple CoO agent. Performance tests of the sealed batteries showed that the positive electrodes with CNT-CoO complex conductive agent exhibited higher discharge voltage, improved capacity, modified discharge stability and prolonged lifespan, especially at high current rates.