Bulletin of Materials Science最新文献

In this paper, a bright, smooth and flexible tin coating on copper surface in methanesulfonic acid was prepared using polyoxyethylene-8-octylphenyl ether (Triton X-100) as surfactant, glutaraldehyde as auxiliary brightener and benzylacetone as brightener through electrodeposition technology, and its morphology, composition and adhesion were characterized by surface analysis techniques and bending tests. In addition, the electrochemical performance of plating solutions containing different additives and the resistance of tin coating to corrosion in a 3.5 wt.% NaCl solution were also investigated using electrochemical testings. The results showed that benzylacetone had stronger adsorption properties than glutaraldehyde, and could effectively suppress the growth of tin dendrites and improve the cathodic polarization ability of plating solutions. When combined, they exhibited higher binding energy on the tin (112) surface and had the highest adsorption stability, making the surface of tin coating smoother, more flexible and more corrosion resistant.

This study investigates the alternating current (AC) losses in pristine and MgB₂-added bulk Bi_1.8Pb_0.20Sr₂Ca₂Cu₃O_10+δ ((Bi, Pb)-2223) superconductors at 77 K. Polycrystalline pellets of (Bi, Pb)-2223 and 0.5, 1 and 2 wt.% MgB₂-added bulk (Bi, Pb)-2223 were synthesized using a solid-state reaction process. X-Ray diffraction (XRD) analysis confirms the presence of (Bi, Pb)-2223 as the primary phase in the crystal structure. Electrical resistivity measurements between 77 and 300 K reveals a decrease in the transition temperature (T_c) and an increase in the transition width (∆T_c) of (Bi, Pb)-2223 with increasing MgB₂ concentration. Diamagnetic response of the samples indicates a decrease in the superconducting volume fraction of (Bi, Pb)-2223 upon MgB₂ addition. Magnetic AC losses were measured as a function of applied magnetic field and frequency. The eddy loss contribution, estimated using the expression reported by Chattopadhyay and Dey [1,15,,2] has a measly contribution and hence confirms the dominant role of hysteresis loss in total magnetic AC losses.

The performance and stability of ITO/PEDOT:PSS Layer 2/P3HT: PCBM Layer 1/ZnO/interface/PEDOT:PSS Layer 1/P3HT: PCBM Layer 2/aluminium tandem organic solar cells are significantly influenced by the thermal annealing process. This study mainly focuses on how the annealing temperature changes the efficiency and overall performance of the solar cells. By systematically varying the working temperature, we investigate its impact on the electrical properties of the active layer, which directly correlates with the device’s photovoltaic performance. The results demonstrate that an optimal temperature improves the charge mobility and reduces recombination. These findings provide valuable insights into the thermal processing P3HT: PCBM tandem organic solar cells, offering a pathway to enhance their durability and practical viability for large-scale solar energy applications. By methodically varying the annealing temperature, we aim to understand the relationship between the temperature and key performance metrics, such as short-circuit current density (J_SC), open-circuit voltage (V_OC), fill factor (FF) and overall power conversion efficiency (PCE). V_OC and J_SC value decrease linearly with increasing temperature. Simulation results show that at 290 K, the device achieves its highest performance with a V_OC of 0.923 V, J_SC of −3.15 mA cm⁻², a fill factor of 39.3% and a PCE of 1.14%. This result paves the way for various opportunities to enhance the performance of P3HT: PCBM based organic solar cells.

In the present research work, SiC-based composite powders were successfully synthesized using the carbothermal reduction reaction (CTR) with high silica iron tailings (IOT) as raw materials; the anthracite culm was used as the carbon source. The effects of different sintering temperatures and carbon contents on the microstructure and phase composition of SiC powders were examined. The order of generation of reaction products during the synthesis of silicon carbide from IOT was also determined by thermodynamic analysis. The results revealed that as the CTR proceeded, the β-phase of SiC was synthesized when sintering was performed at 1500°C at a SiO₂/C molar ratio of 1:5.5 for 4 h, and the secondary crystal type was the Fe-Si compound. Thermodynamic studies showed that the presence of iron oxides in the IOT aided the synthesis of the SiC phase by CTR, a mineral phase with a high melting point, at a lower temperature. The present study thus provides significant guidance for the secondary utilization of IOT.

The elementary and critical process in dielectric capacitors is interfacial charge separation. In this work, we propose the synthesis and investigation of the optical, electrical and dielectric properties of a WO₃·H₂O/W₁₈O₄₉ heterojunction with optimized oxygen vacancies for efficient charge storage applications. Tungsten-oxide-based heterojunctions were synthesized via a co-precipitation method using varying HCl concentrations. XRD analysis confirmed the formation of distinct phases, while XPS and Raman spectra revealed effective charge transfer and structural defects. UV-DRS studies highlighted the formation of oxygen-deficient m-W₁₈O₄₉. Enhanced dielectric constant, low impedance and increased conductivity were observed, particularly with low HCl concentrations, due to improved interfacial charge separation in WO₃·H₂O/W₁₈O₄₉ heterojunction. These properties make the WO₃·H₂O/W₁₈O₄₉ heterojunction a promising candidate for energy storage applications, offering significant advantages such as improved cyclic stability, power density and reduced heat generation.

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This study investigates the enhancement of thermal stability and flame-retardant properties of textile materials through the incorporation of hydroxyapatite grafted with varying percentages of aminotrimethyl phosphonate (HAp–AMP). Using a MATHIS type SV manual coating machine, textiles were treated with different concentrations of AMP–HAp (2.5, 5, 10 and 20%) in a polyamide (PA) matrix. The mechanical properties, thermal stability and flame resistance of the treated fabrics were evaluated through standardized tests, including tensile strength and elongation measurements according to NF EN ISO 13934-1: 2013, thermogravimetric analysis, and flame tests per NF EN ISO 6940:2004–08. The results indicate significant improvements in the thermal and flame-retardant performance of the coated fabrics. Higher concentrations of AMP–HAp demonstrated superior resistance to thermal degradation and flame propagation, with the PA + 15 AMP–HAp sample showing the most robust performance. Scanning electron microscopy confirmed the formation of a uniform and dense coating layer, contributing to the enhanced properties. The study concludes that AMP–HAp coatings effectively improve the flame retardancy and durability of textiles, making them suitable for applications requiring high thermal and fire resistance.

To address the corrosion of mild steel in aggressive mine water environments, nickel-chromium-iron (Hastelloy^® G30), copper-nickel-tin (ToughMet^® 3), and cobalt-chromium-tungsten (Stellite^® 6B) alloys were evaluated for their corrosion resistance. The study examined their behaviour in synthetic mine water at pH levels 6, 3 and 1 using potentiodynamic polarisation, alongside microstructural, hardness, and X-ray diffraction (XRD) analyses. Hastelloy^® G30 had equiaxed γ grains with Cr₃C₂ precipitates, ToughMet^® 3 displayed large, irregular grains, and Stellite^® 6B showed γ grains with Cr₃C₂ at boundaries and twinning. Hastelloy^® G30 and Stellite^® 6B demonstrated active-passive transitions with localized corrosion, while ToughMet^® 3 showed pseudo-passivation with severe pitting across all pH levels. Hastelloy^® G30 achieved the lowest corrosion rates at pH 6 (0.63 ± 0.01 µm·y^–1) and pH 3 (0.74 ± 0.05 µm·y^–1) but performed poorly at pH 1 (7.75 ± 0.64 µm·y^–1), with a hardness of 180 ± 10 HV₂. Stellite^® 6B had low corrosion rates at pH 3 (1.32 ± 0.34 µm·y^–1) and pH 1 (5.61 ± 1.13 µm·y^–1), with a hardness of 368 ± 13 HV₂. ToughMet^® 3 showed high corrosion rates, particularly at pH 1 (118.78 ± 8.00 µm·y^–1). Stellite^® 6B is the most promising alternative for harsh mining environments, offering optimal hardness and corrosion resistance.

The growth of the pre-immersion and anodic surface oxide films on titanium was found to be influenced by the pH of the saliva using open-circuit potential (E_ocp), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. It was found that the titanium's E_ocp increased with time as the metal was immersed in saliva with different pH values, from acidic to alkaline. This suggests that the titanium's pre-immersion oxide coating grew in these solutions. Furthermore, the EIS data showed that the oxide film resistances of both anodic and pre-immersion films increased with the saliva's pH, although anodic films did so faster than the pre-immersion films. Even though titanium's pre-immersion coating grows in neutral saliva that contains fluoride ions (F^– ions), the corrosion resistance of the metal diminishes as the concentration of these ions rises because of their aggression. The results of potentiodynamic polarization demonstrated that the rate of corrosion of the titanium surface was reduced by both an increase in pH and a decrease in fluoride ion concentration in saliva. The resistance of titanium's pre-immersion layer increased when the immersion period was raised to 17 days in saliva containing 0.005 M F^– ions at pH 6.34. The titanium surface was examined using scanning electron microscopy (SEM), and it was shown that when the pH of saliva increases, a greater percentage of the faults and notches on the growing pre-immersion oxide layer are repaired and healed. Additionally, the atomic force microscopy (AFM) data demonstrated that the titanium's surface roughness increases with the concentration of F^– ions in saliva due to their corrosive action. Energy dispersive spectroscopy (EDS) revealed that a titanium oxide layer was formed when titanium was submerged in artificial saliva.

The doubly ordered perovskites, NaYFeWO₆ and NaHoFeWO₆, have been synthesized by high pressure (4.5 GPa) and high temperature (1000ºC) methods. Powder X-ray diffraction (PXRD) analysis has confirmed that these compounds crystallize in the monoclinic structure with the space group P2₁. These materials exhibit distinct layer ordering of A-site cations (Na and Ln) and a common rock-salt ordering of cations (Fe, W) in B-site. Magnetic, heat capacity and dielectric data, reveal antiferromagnetic ordering of NaYFeWO₆ (T_N ~ 13 K), and NaHoFeWO₆ (T_N ~ 15 K) accompanied by a dielectric anomaly. Although pyroelectric and DC-bias current measurements were impacted by leakage currents, variations in these currents were detected near the magnetic ordering temperatures. The dependence of dielectric, pyrocurrent and DC-bias anomalies on the magnetic field suggests that these compounds exhibit multiferroic behaviour.

Sensing of explosive molecules for defence application was done using freely positionable and fibre coupled Raman probe. We developed the highly sensitive Ag-based array of surface enhanced Raman substrate (SERS) using a nanoimprint lithography. A limit of detection (LOD) as low as 10^–9 M for Cyclotetramethylene-tetranitramine (HMX) was achieved with long distance detection of 10 m. The optical fibre length could be customized from 1 to 10 m. This is the upcoming remote technique for sensing, using fibre coupled Raman probe, containing 20x objective present just in front of the optical fibre, so that the background signal does not dominates. An enhancement factor of 3.11 × 10⁶ was achieved with the limit of detection as 10^–9 M and it finds useful application in defence and medical field.