Increasing Oxide Content Research Articles

Effect of Sm2O3 on thermal, optical, mechanical, gamma and neutron shielding properties of zinc-boro-vanadate glasses

Abstract The effect of Sm2O3 on thermal, optical, mechanical, gamma and neutron shielding properties of newly prepared zinc borovanadate glasses has been investigated. Density is found increased and molar volume decreased with Sm2O3 content. The glass transition temperature ( T g ) , crystallization temperature ( T c ) and the peak crystallization temperature ( T P ) increased with increase of rare earth oxide content. These findings demonstrated an excellent glass-forming ability and thermal stability of the glasses. The optical properties have been explored through UV–vis spectroscopy. The indirect optical band gap energy ( E opt ) decreased from 2.978 to 2.679 eV, Urbach energy ( ∆ E ) increased from 0.273 to 0.299 eV and refractive index increased from 2.403 to 2.489 with increase in Sm2O3. Elastic moduli, Poisson’s ratio, Hardness and fractal bond connectivity were computed theoretically as per Makishima Mackenzie model. It is found that these glasses have appreciable mechanical strength and rigidity. Phy-X/PSD software has been used to determine different radiation shielding characteristics for the energy range 0.015–15 MeV. The mass and linear attenuation coefficients are found higher, and half value layer, tenth value layer and mean free paths are found lower than many radiation shielding glasses quoted in the literature values. The obtained Z eq values varied from 15.828–29.118 for energy range from 0.015 to 15 MeV, which are greater than those reported for several commercial glasses, concretes and rocks. Due to the Compton scattering process, exposure build up and energy absorption factor are found to be highest in the medium energy region. The fast neutron removal cross-sections of the glasses are observed to be significantly high. For the first time, thermally stable and mechanically strong zinc borovanadate glasses mixed with Sm2O3 have been thoroughly investigated for various properties and concluded that these glasses are suitable for optoelectronics and γ-shielding applications.

High-speed laser cladding (Fe,Cu)-dopped Ni-Co protective coatings for SOFC MICs: From long-term oxidation behavior to mechanical stability

The long-term operation of intermediate temperature-solid oxide fuel cells (IT-SOFCs) could be significantly influenced by the stability of the interconnect itself, especially, its oxidation resistance under the cathode environment. To effectively prevent Cr-volatilization and improve the interconnector performance, application of highly dense and stable protective coatings over the interconnector is indispensable. In this work, Ni-Co-based alloy protective coatings doped with Fe and Cu were applied onto the 441 interconnector via a novel high-speed laser cladding technology. The microstructure evolution, phase composition, oxidation resistance, electrical conductivity and mechanical properties of the coated steels were investigated at different oxidation stages at 800 °C. It was found that the Ni33.8Co34Fe32.2-coated steel shows the best oxidation resistance and electrical properties. The oxidation rate (kp) and ASR of Ni33.8Co34Fe32.2-coated steel is respectively 4.44 × 10−13 g2 cm−4 s−1 and 25.55 mΩ cm2, significantly lower than the uncoated steel and Ni44.6Co44.7Cu10.7-coated steel at the end of 1000-h test cycle. The resultant conductivity of the Ni44.6Co44.7Cu10.7 and Ni33.8Co34Fe32.2-coated steels is approximately 7.8 and 4.1 S cm−1, respectively, which could meet the requirement for SOFC stacks. In addition, the nano-hardness of the Ni33.8Co34Fe32.2 and Ni44.6Co44.7Cu10.7-coated steels was found to be 8.3 GPa and 8.8 GPa, respectively, through nanoindentation testing. The improved surface hardness is attributed to grain refinement and increased oxide content on the coating surface. The results indicated that the Ni-Co-based alloy coatings effectively improved the long-term stability and mechanical property of the 441 interconnector under the SOFC cathode environment.

Extending the upper limit of volumetric fraction of oxides in ODS-Cu fabricated with internal oxidation via element doping

In general, when the oxide content is controlled within 5 wt%, increasing the content of oxides is crucial for improving the strength, hardness, and wear resistance of oxide dispersion strengthened copper alloy (ODS-Cu). However, the oxide content of commercially available ODS-Cu fabricated with internal oxidation (e.g. Glidcop-60) is limited to 1.1 wt% due to the adverse effects of irregular growth of oxide particles on overall properties when the oxide content increases. In this study, we introduced oxide particles into Cu matrix via internal oxidation of Cu-Al and Cu-Al-Ti alloys using Rhines-pack method. The origin of irregular oxide particles, oxide bands and healing layers formed in the oxidized layer of the ODS-Cu alloys with high oxide content was revealed. Furthermore, it is found that the doping of Ti can effectively suppress the growth of irregular oxide particles and the formation of oxide bands. In the specimens with a Ti/Al molar ratio of 0.28, Ti has a better inhibitory effect on oxide particle coarsening, and this inhibitory effect is more pronounced when ODS-Cu containing higher oxide content. Compared to Cu-0.6 %Al alloy, the average occurrence and length fraction of oxide bands in Cu-0.6 %Al-0.3 %Ti alloy are significantly reduced (by 81 % and 95 % respectively), and the fraction of oxide particles smaller than 20 nm is significantly increased (from 5 % to 76 %). This Ti-doping strategy solves the dilemma in increasing the oxide content in ODS-Cu produced by internal oxidation, and also provides the possibility for industrial production of high oxide volumetric fraction ODS-Cu with internal oxidation.

Optimizing the composition of barium-borate glasses for enhancing thermal neutron shielding efficiency: Monte Carlo simulation

A transparent window with thermal neutron shielding properties was an important part of the stations of the nuclear reactors and the particle accelerators. The borate glass with a high neutron cross section was a candidate as a glass network for the neutron shielding window. In order to slow down thermal neutrons, they were trapped by boron and subsequently emitted secondary radiation, such as alpha particles and gamma-ray radiation. This work was to optimize the content between a ratio of borate with a high cross-section neutron interaction and barium for shielding alpha and gamma ray. The barium-borate glasses were successfully synthesized using the melting technique in the atmosphere. Measurements of mechanical and optical glass properties were presented. The measured results showed that an increase in barium oxide content in the glass ratio enhanced the glass density and the transmittance at a visible wavelength. In the calculation of radiation shielding properties, FLUKA code based on Monte Carlo Simulation was demonstrated. The calculated results revealed that an increase in the barium oxide content in the glass composition reduced the thermal neutron shielding properties of the glass samples. In contrast, the glass with barium contents enhanced the photon-shielding efficiency, as indicated by the mass attenuation coefficient and half-value layer. Not only the ratio of the barium and borate contents affected the shielding properties, but the increased glass thickness also enhanced the shielding properties. Thus, the utilization of cooperative borate glasses and barium with appropriate thickness could potentially serve as a viable option for simultaneously protecting against thermal neutrons and photons. The barium-borate glasses with our composition might be used as a window in a thermal neutron station as well as for photon radiation.

Effect of Heat Treatment on the Electrochemical and Tribological Properties of Aluminum-Bronze Coatings Deposited Used the Thermal Spraying Process

The corrosion and wear resistance of aluminum-bronze coatings deposited by thermal flame spraying were investigated after a 10 h heat treatment at 500 °C in a nitrogen atmosphere. The coatings were characterized by SEM, EDS, XRD, and XRF. Corrosion resistance was evaluated by Tafel and EIS tests, while wear resistance was assessed using a ball-on-disc test. Results showed the heat treatment compacted the coating microstructure, increased oxide content, and improved splat bonding through diffusion mechanisms. This led to enhanced corrosion resistance, evidenced by reduced corrosion current density in electrochemical tests, resulting from densification impeding electrolyte penetration. Heat treatment also increased wear resistance, as indicated by lower wear rates in ball-on-disc tests, attributable to increased hardness, reduced friction coefficients, and annealing-induced microstructural changes. Overall, the heat treatment optimizes the anticorrosive and tribological properties of thermally sprayed aluminum-bronze coatings via favorable alterations in composition, morphology, and physical characteristics. The research provides a new understanding of how thermal spray parameters and post-deposition heat treatment can be utilized to enhance the corrosion and wear resistance of aluminum-bronze coatings for marine applications.

Synthesis of Y2O3 and graphite-added copper-based hybrid composites by powder metallurgy: Mechanical properties and tribological behavior

In the presented study, Y2O3 and graphite-reinforced Cu matrix hybrid composite materials were prepared using the powder metallurgy method. The aim is to compare the microstructure, density, hardness, and wear behavior of composites with different yttria contents (5, 10, and 15 weight%) and graphite (2 weight%) reinforcements. An increase in the Y2O3 ratio, along with the addition of graphite, resulted in an observed increase in the hardness values of the composites. Additionally, it was observed that Y2O3 and graphite are homogeneously distributed in the copper matrix in the SEM-EDX spectra. Upon examining the microstructures of the composites, it was determined that with the increase in yttrium oxide content, partially yttrium oxide agglomerations formed in some regions. The addition of Y2O3 resulted in a copper sample that is 1,34 times harder than pure copper. Addition of Y2O3 -graphite, samples with 3.301-22.3 % higher wear resistance were obtained.

Microfluidic preparation and thermal properties of HMX@PDA@MO

Metal oxides can effectively promote the thermal decomposition of energetic materials. However, the traditional physical mixing process has potential safety hazards and cannot achieve uniform and stable coating. To address this issue, this study provides adhesion sites for metal oxides through the rough coating formed by polydopamine on the surface of HMX, which improves the coating stability. Taking advantage of the safety and efficient mixing of microfluidic technology, HMX@PDA@MO samples with good dispersion were prepared. The samples were characterized by SEM-EDS, XRD and DSC. The XRD results demonstrate the successful preparation of HMX@PDA@CuO and HMX@PDA@PbO samples. SEM-EDS images show that polydopamine forms a rough coating on the surface of HMX, and the increase in the total flow rate is beneficial to enhance the dispersion of metal oxides. The DSC data showed that the addition of 3% and 20% CuO advanced the thermal decomposition temperature and apparent activation energy of HMX@PDA by 0.3K, 40.13 kJ·mol−1 and 2K, 108.83 kJ·mol−1, respectively, PbO is 0.1K, 111.94 kJ·mol−1, and 4.5K, 205.02 kJ·mol−1. It shows that the increase of metal oxide content will promote thermal decomposition. For HMX, PbO has better catalytic activity than CuO. PbO has better catalytic activity than CuO for HMX.

Stimulating Role of Calcium and Cyclic GMP in Mediating the Effect of Magnetopriming for Alleviation of Salt Stress in Soybean Seedlings

This current study examined the role of calcium (Ca) and Cyclic GMP (cGMP) in mitigating the adverse effect of salt stress through magnetopriming of soybean cultivar JS-335 seeds with a static magnetic field (SMF, 200 mT for 1 h). The salt stress (50 mMNaCl) extensively reduced the early seedling growth (64%), vigour Index-I (71%), vigour Index-II (39%), total amylase (59%), protease (63%), and nitrate reductase (NR, 19%) activities in un-primed soybean seedlings. However, magnetopriming and Ca treatment enhanced all of these measured parameters along with remarkable increase in reactive oxygen species (ROS) and nitric oxide (NO) content. The exogenous application of Ca2+, cGMP and ROS regulators such as nifedipine (Ca2+ channel blocker), EGTA, ethylene glycol-β-amino ethyl ether tetra acetic acid (Ca2+chelators), genistein (cGMP blocker), and dimethyl thiourea (DMTU, H2O2 inhibitor) negatively affects the SMF-induced seedling length, seedling vigour, ROS, NO, and enzyme activities such as protease, total amylase, and NR in soybean seedlings. Results presented by using specific various biochemical inhibitors of Ca, cGMP, or ROS signalling in vivo indicated that Ca and cGMP are also involved with ROS and NO in the signal transduction of magnetic field enthused soybean seed germination and seedling growth under salt stress.

Assessment of sol-gel derived iron oxide substituted 45S5 bioglass-ceramics for biomedical applications.

Magnetic bioactive glass-ceramic (MGC) powders with nominal compositions of (45 - x)SiO224.5CaO24.5Na2O6P2O5xFe2O3 (x = 2, 4, 6, 8, 10, and 15 wt%) have been synthesized by a sol-gel route by systematically substituting silicon dioxide with iron oxide in Hench's 45S5 glass composition. Powder X-ray diffraction studies revealed a variation in the percentage of combeite (Ca2Na2Si3O9), magnetite (Fe3O4), and hematite (Fe2O3) nanocrystalline phases in MGC powders as a function of composition. Zeta potential measurements showed that MGC containing up to 10 wt% iron oxide formed stable suspensions. The saturation magnetization and heat generation capacity of MGC fluids increased with an increase in iron oxide content. Degradation of MGC powders was investigated in phosphate buffered saline (PBS). The in vitro bioactivity of the MGC powders taken in pellet form was confirmed by observing the pH variation as well as hydroxyapatite layer (HAp) formation upon soaking in modified simulated body fluid. These studies showed a decrement in the overall bioactivity in samples with high iron oxide content due to the proportional decrease in the silanol group. Monitoring the proliferation of MG-63 osteoblast cells in Dulbecco's Modified Eagle Medium (DMEM) revealed that MGC with up to 10 wt% iron oxide exhibited acceptable viability. The systematic study revealed that the MGC with 10 wt% iron oxide exhibited optimal cell viability, magnetic properties and induction heating capacity, which were better than those of FluidMag-CT, which is used for hyperthermia treatment.

Synergetic Effect of CeO2 Doping on Structural and Tribological Behavior of Fe-Al2O3 Metal Matrix Nanocomposites

Cerium oxide (CeO2) doped iron (Fe) - alumina (Al2O3) Metal Matrix Nanocomposites have been studied in this article. Doped with 0.5 and 1.0 percent CeO2, the nanocomposites in this system were made in the lab. Weighing, Powder milling, die pressing, and sintering at 1100 °C for one hour in an atmosphere-controlled furnace were used to develop the specimens. Microstructural inspection of a worn-out surface on the prepared specimens was carried out in addition to the phase determination and microstructural assessment that were performed on the fabricated specimens. Fe, Al2O3, CeO2, and FeAl2O4 phases were all seen in the XRD data. There were nano dispersion of FeAl2O4 and CeO2 particles in the dense phase microstructure of the produced samples. Increasing the amount of cerium oxide in the material resulted in an increase in both density and hardness. The specimen’s wear rate was shown to decrease with an increase in cerium oxide content %. The present developed material will be useful for heavy duty applications like railway wagon wheels.

Recycling of granite powder and waste marble produced from stone processing for the preparation of architectural glass–ceramic

• Glass-ceramic was prepared using granite powder and waste marble by melting-sintering method. • The addition of MgO changes the main crystalline phase of the glass–ceramic from wollastonite to augite. • The acid resistance of glass-ceramics is weakened with the increase of basic oxide content in the chemical composition. • The glass–ceramic with flexural strength of 146.95 MPa and Vickers hardness of 10.24 GPa can be achieved. A large amount of solid waste is generated during the stone processing, and a serious environmental issues has arisen from the accumulation of these wastes. In this work, granite powder and waste marble are used to prepare architectural glass–ceramic. The mechanical properties, microstructure, and acid resistance of glass-ceramics designed with different compositions were investigated. With the increase of waste marble content, the main crystalline phase of glass–ceramic changed from anorthite to wollastonite, and the flexural strength of glass–ceramic was also enhanced. When the mass ratio of granite powder to waste marble is 40:60, a CaO-Al 2 O 3 -SiO 2 (CAS) glass–ceramic with a flexural strength of 109.33 MPa and a Vickers hardness of 6.61 GPa is obtained. After the addition of MgO, the main crystalline phase of the glass–ceramic is augite. Under the addition of 5 wt% MgO, the flexural strength and Vickers hardness of CaO-MgO-Al 2 O 3 -SiO 2 (CMAS) glass–ceramic reached the maximum, which are 146.95 MPa and 10.24 GPa, respectively. The mechanical properties of these two types of glass-ceramics developed from granite powder and waste marble can meet the requirements of building materials. From the acid resistance test results, it was found that the higher the content of MgO and CaO in the chemical composition of glass–ceramic, the worse the acid resistance. Therefore, the basic oxide content should be carefully controlled in the composition design of glass–ceramic. This technology of converting granite powder and waste marble into value-added glass–ceramic provides a promising method for the utilization of solid waste from stone processing, which can greatly improve the sustainability of the stone industry.

Dielectric properties and ac conductivity of CuO and Fe2O3 doped polycarbazole nanocomposites

This paper presents results and discussion on dielectric and ac conductivity of Polycarbazole (PCz) and its PCz/CuO and PCz/Fe2O3 nanocomposites. Samples were prepared by oxidation method using ammonium persulfate as oxidizing agent. Samples were confirmed to be crystalline. Dielectric parameters are observed to be decreased with increase of frequency and temperature. Ac electrical conductivity of pure polycarbozole was found to be more than the composites. Further, conductivity increased with loading of metal oxide nanoparticles. The conductivity of all the samples is found to vary from 10-6 (Ωm)-1 to 10-4 (Ωm)-1 with the temperature (303K- 423K) and exhibited semiconducting nature. This has been ascribed to rise in the number of charge clusters inside polymer matrix with increase of metal oxide content and which in turn adds more polarons to the conduction band and, that increase conductivity. Activation energy for conduction is determined to vary from 1.07 meV to 6.17 meV for PCz/CuO systems and 0.82 meV to 4.06 meV for PCz/Fe2O3 composites. It is for the first time that Polycarbazole and Polycarbazole metal oxide doped nanocomposites have been studied for dielectric properties and ac conductivity over wide a range of frequency and temperature and analyzed data with respect to frequency, temperature and metal oxide content.

Analysis of Thermogravimetric and Dynamic Mechanical Properties of PLA/PBS Blends Doped With Zinc Oxide Nanoparticles

Abstract In the present work, PLA-PBS blends of 80/20 weight ratio were doped with zinc oxide (2.5; 5; 7.5 and 10 phr) and the flow, thermogravimetric and thermomechanical behaviour of the resulting blends were investigated. Using capillary plasstometry, thermogravimetry (TGA) and dynamic mechanical analysis (DMA), it was found that the increase in zinc oxide content resulted in an increase in the flow indices (MFI, MVR), as well as in the storage and loss modulus values, and a decrease in the thermal stability and glass transition temperature.

Effect of potassium or yttrium introduction in Yb3+-doped germano-gallate glasses on the structural, luminescence properties and fiber processing

Here we report on the effect of potassium or yttrium on the luminescence spectroscopic properties of Yb3+-doped germano-gallate glasses as well as the ability to shape them into optical fibers with the objective of using such glasses to produce near-infrared optical gain medium. Two ytterbium-doped germano-gallate glass systems, (100-x) (28Ga2O3 – 37GeO2 – 23BaO – 12K2O) – xYb2O3 (x = 0, 0.5 and 3 mol.%) and 29.6Ga2O3 – 39.1GeO2 – 24.3BaO – 7 (yY2O3 – zYb2O3) (y = 6.5, 4, 0 and z = 0.5, 3, 7 mol% respectively) have been prepared and the systematic investigation of their thermal, structural, optical and spectroscopic properties have been carried out. The increase in ytterbium oxide content leads to an increase of the glass transition temperature, crystallization temperature and the density of the glasses, as well as induces a red-shift of the cut-off wavelength. Raman spectroscopy analysis shows that both ytterbium oxide addition and potassium substitution by yttrium modify the 3D interconnected germano-gallate glass network. Lifetime diminishes with the increase of Yb3+ concentration but remains higher in the yttrium-containing glasses. We demonstrate that the production of crystal-free light guiding fibers via the preform-to-fiber approach becomes possible only in the yttrium-containing glass system. Cut-back optical attenuation measurements of the produced fibers show minimum losses of 3.3 dB/m at 1310 nm.

Structural and oxide-based colours on laser textured copper

Laser texturing to create colours has recently attracted significant interest due to the rapid and non-contact nature of the technique. The complex optical response of femtosecond laser-textured copper surfaces, producing a palette of perceived colours with varying amounts of angle dependence, is presented. The colours depend on the line spacing used in the laser raster-scanning process. Grazing angle Fourier transform Infrared spectroscopy (FTIR) and Raman microscopy show increased oxide content with larger total accumulated fluence and increased pulse overlap. The increased oxide content coincides with a greater angle independence of the colours compared to colours obtained at larger line spacings. All samples have a similar sinusoidal periodic microstructure, with amplitudes ranging from 400 nm for the smallest line spacings (∼1 µm) to 100 nm for the largest line spacings (∼20 µm), and are decorated with nanoparticles. The angle dependence of the colours is quantified using reflectance measurements, which show a shift in reflectance peak with observation angle. The overall complex colour of the surfaces is attributed to a combination of copper oxides and structural colours driven by underlying nanoparticles, be they metal or metal-oxide, and sinusoidal gratings with a pitch of approximately 1 µm.

Nonlinear optical birefringence in Li2SO4-MgO-P2O5 amorphous system -influence of Cu ions

Li2SO4-MgO-P2O5 glasses doped with varied contents of CuO (from 0- 1.0 mol%) were prepared. The optical birefringence induced by a High Q-2 femtosecond pulsed laser is explored as a function of copper oxide concentration in these glasses. The magnitude of the light-induced birefringence exhibited a gradual decrease with the increase of copper oxide content. The observed behavior is discussed in terms of polymerization of the glass network, the degree of which rises with concentration of Cu+ ions occupying Td sites in the glass matrix. However, the samples containing low content of CuO are dominated by Cu2+ ions that act as modifiers and induce structural imperfections by breaking of P-O-S bonds. Accordingly, the samples mixed with lower content of CuO are more favorable for inducing higher magnitudes of the optical birefringence. This conclusion is corroborated by results of electrical conductivity, positron annihilation and ultrasonic measurements.

Effects of solid–liquid doping and spark plasma sintering on the microstructure and mechanical properties of Y2O3-doped copper matrix composites

High-strength and high-conductivity copper alloys have a wide range of applications, such as an important electrical contact material. In this work, Cu–Y2O3 composite material was prepared through solid–liquid doping, calcination reduction, and spark plasma sintering. The effect of different yttrium oxide content (1, 3, and 5 wt%) on the microstructure and mechanical properties of the composite was studied. Results showed that the surface of the calcined and reduced copper powder was uniformly covered with yttrium oxide particles. After spark plasma sintering, the relative density of the blocks almost reached 100%. With the increase in yttrium oxide content, the distribution of yttrium oxide transformed from dispersion to agglomeration, and the grain size gradually decreased. There is a good bond between the copper matrix and yttrium oxide, and the particle size of yttrium oxide particles is approximately 150 nm. In terms of mechanical properties, the Cu-3wt.% Y2O3 sample obtained the best comprehensive mechanical properties with strength of 290.1 MPa, hardness of 125.7 HV, and conductivity maintained at a high level of 95% International Annealed Copper Standard (hereinafter called IACS).

Effect of lead oxide on the electrical transport properties of lithium–iron–borate glasses

The electrical conductivity and dielectric properties of the glass system (70-x) B2O3–(x) Pb3O4–10Fe2O3–20Li2O [where 0 ≤ x ≤ 35] have been investigated in the temperature range from 300 to 530 K, at four fixed frequencies [0.12, 1, 10, and 100 kHz]. Ac conductivity is found to obey the universal relation, σ(ω) = Aωs, where s is the frequency exponent factor and its value is less than unity. Investigation of σac results and the s factor reveals that the polarons hopping over barrier between Fe2+ and Fe3+ ions is the probable applicable mechanism for σac for these glasses. The dc activation energy values are found to increase from 0.67 to 1.61 eV as the lead oxide content increases. These remarks are explained using Mossbauer Effect (ME) spectrometer and molar volume calculations. The observed higher records of the dielectric constant for the lead-free sample could be attributed to some precipitated iron in the form of α-Fe2O3, which increases the polarized space charges in the glass network.

Atomic Layer Deposition of Ni-Co-O Thin-Film Electrodes for Solid-State LIBs and the Influence of Chemical Composition on Overcapacity.

Nanostructured metal oxides (MOs) demonstrate good electrochemical properties and are regarded as promising anode materials for high-performance lithium-ion batteries (LIBs). The capacity of nickel-cobalt oxides-based materials is among the highest for binary transition metals oxide (TMOs). In the present paper, we report the investigation of Ni-Co-O (NCO) thin films obtained by atomic layer deposition (ALD) using nickel and cobalt metallocenes in a combination with oxygen plasma. The formation of NCO films with different ratios of Ni and Co was provided by ALD cycles leading to the formation of nickel oxide (a) and cobalt oxide (b) in one supercycle (linear combination of a and b cycles). The film thickness was set by the number of supercycles. The synthesized films had a uniform chemical composition over the depth with an admixture of metallic nickel and carbon up to 4 at.%. All samples were characterized by a single NixCo1-xO phase with a cubic face-centered lattice and a uniform density. The surface of the NCO films was uniform, with rare inclusions of nanoparticles 15–30 nm in diameter. The growth rates of all films on steel were higher than those on silicon substrates, and this difference increased with increasing cobalt concentration in the films. In this paper, we propose a method for processing cyclic voltammetry curves for revealing the influence of individual components (nickel oxide, cobalt oxide and solid electrolyte interface—SEI) on the electrochemical capacity. The initial capacity of NCO films was augmented with an increase of nickel oxide content.

Effects of ash compositions in Zhundong coal on its ash fusion behavior and crystal phase transformation

AbstractThe ash‐related issues hinder the safe utilization of Zhundong coal, closely relevant to its ash compositions. Previous studies mainly focused on the experimental methods and the selection of ash composition benchmark was restricted to a specific coal sample with limited element types, ignoring the comprehensive elemental interaction. Here, the impacts of eight compositions on ash fusion and crystal phase transformation behaviors were taken into consideration. Moreover, FactSage software was employed to further elucidate the transformation mechanism of ash composition with the increasing temperature. The results showed that the refractory forsterite and merwinite disappeared but more magnesioferrite was present with an increase in ferric oxide content, resulting in the decrease of ash fusion temperatures. The refractory substances, such as forsterite, perovskite, periclase, and larnite, occurred successively with the increasing ratio of basic oxide to acid oxide. The slag content had reached its maximum at 1200°C, up to 90% as the content of CaO was 16%, which was corresponding to that the flowing temperature descended to the lowest point around 1200°C with 16% CaO. With the rising temperature, more slag appeared and the composition species declined, related with the generation of fusible compounds containing Fe and Na at high temperature. The present work can play a guiding role in safe and clean use of Zhundong coal.