Showing 190 results for Tic
Ali Keramatian, Mohammad Hossein Enayati, Fatemehsadat Sayyedan, Sima Torkian,
Volume 22, Issue 2 (6-2025)
Abstract
The aim of this study was to investigate the effect of current density on the microstructure of electrodeposited Ni–WC–TiC composite coatings on 304 stainless steel and compare the corrosion resistance of the coating and substrate in a 3.5 wt.% sodium chloride solution. A Watts nickel bath was employed under direct current (DC) conditions. Microstructure, elemental composition, and phase composition analyses were conducted using scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD), respectively. The results revealed that the coating formed at a current density of 40 mA/cm² exhibited a denser microstructure with higher cohesion and uniformity compared to coatings produced at other current densities. The corrosion resistance of the coating and substrate was evaluated using Tafel and electrochemical impedance spectroscopy (EIS) analyses. The corrosion test results indicated that the substrate exhibited superior corrosion resistance compared to the coating. Based on the dynamic polarization test plots, the corrosion mechanism of the substrate is active-quasi passive, with a pseudo-passive layer forming on the sample which remains stable within the potential range of -0.17 to 0.17 V. Beyond this potential range, the sample becomes susceptible to pitting. In the coated sample, the corrosion behavior is similar to that of the substrate, with the exception that the pseudo-passive layer remains stable within a narrower potential range of -0.19 to 0.08 V.
Y C Goswami,
Volume 22, Issue 3 (9-2025)
Abstract
CuS nanoparticles (NPs) with dimensions in the nanometer range were synthesized using a wet chemical approach. The comprehensive characterization of these NPs involved an analysis of their structure, composition, and optical properties, primarily conducted through X-ray diffraction (XRD) analysis. The XRD pattern conclusively confirmed the presence of the hexagonal phase in the CuS particles, a result corroborated by the accompanying Raman spectrum. The investigation further determined an estimated bandgap energy of 2.05 eV for the slightly sulfur-rich CuS NPs. Notably, this energy value exceeds that of bulk CuS (1.85 eV), indicating a noticeable miniaturization effect. The novel CuS NPs exhibited outstanding photocatalytic activity in the degradation of methyl Red (MR), particularly under visible light. This impressive performance is attributed to surface-bound OH ions on the CuS nanostructures, facilitating the adsorption and acceleration of the degradation process for MR molecules under visible light irradiation. The research presented in this article highlights the significant promise and efficiency of the synthesized CuS NPs as photocatalysts. These nanoparticles are particularly responsive to stable visible light, making them highly suitable for purifying chemically contaminated wastewater. Specifically, their effectiveness in degrading stable azo dyes, exemplified by MR, underscores their potential in practical applications.
Mohammad Abdullah Al Asad, Hasan Ridoy, Md. Shuzon Ali, Mst. Jeba Maimuna,
Volume 22, Issue 3 (9-2025)
Abstract
Perovskite materials have accumulated considerable attention in recent years for their exceptional electro-optical properties, creating them rising candidates for various uses in the fields of photovoltaics, light-emitting devices, and beyond. Among these perovskite materials, CsPbI3 stands out as a notable example due to its remarkable stability, tunable bandgap, and efficient light-emitting properties. The crystal structure, composition, and introductory properties of CsPbI3 perovskite using density functional theorem (DFT) being focused. In detailed exploration of Electronic property, Elastic property, Optical property, Population analysis, and shedding light on the unique attributes of this material highlighted this study. To do above computation we have used CASTEP in Material Studio.
Salahaldin Mansur Alduwaib, Reihane Etefagh, Boshra Ghanbari Shohany,
Volume 22, Issue 3 (9-2025)
Abstract
This research is focused on the synthesis of zinc oxide nanoparticles by means of the sol-gel conventional method, followed by the formulation of a zinc oxide-polypropylene (ZnO: PP) masterbatch using a twin-screw extruder. The next step involved the fabrication of antibacterial fibers through electrospinning. The resulting Nano powders, masterbatch, and fibers were subjected to a series of characterization techniques. X-ray diffraction (XRD) was used to examine the crystalline structure, field emission scanning electron microscopy (FESEM) was employed to scrutinize the morphology of the samples, energy-dispersive X-ray spectroscopy (EDX) was adopted for elemental analysis, and Fourier-transform infrared spectroscopy (FTIR) was hired to identify the chemical bonds.
Thermogravimetric analysis (TGA) indicated a three-stage weight loss process, and differential scanning calorimetry (DSC) showed a primary endothermic peak centered at about 317 °C and a pronounced exothermic peak at approximately 455 °C. XRD confirmed the hexagonal wurtzite structure of the zinc oxide nanoparticles and the presence of the alpha (α) crystal form in polypropylene. FESEM imaging revealed that the zinc oxide and masterbatch samples had a uniform size and shape, predominantly in the nanometer range with an elongated spherical morphology. The antibacterial properties of polypropylene fibers containing varying concentrations of zinc oxide, including 1.2, 2.4, and 5 wt.%, were tested against Escherichia coli and Staphylococcus aureus.
Azam Bayat,
Volume 22, Issue 3 (9-2025)
Abstract
The lindgrenite compounds [Cu3(MoO4)2(OH)2] with various architectures and high crystallinity were prepared by a simple surfactant-assisted hydrothermal method. Then, the Cu3Mo2O9 samples were prepared by calcination of the as-synthesized Cu3(MoO4)2(OH)2. The resulting samples had high crystallinity, colloidal properties, high-yield, large-scale production capability with using of nontoxic and inexpensive reagents and water as an environmentally solvent. The scanning electron microscope studies showed that the as-prepared lindgrenite nanostructures were well crystallized with rod, sheet and hollow sphere morphologies. These products were content of the Cu3(MoO4)2(OH)2 rods with diameters of about 100 nm, the Cu3(MoO4)2(OH)2 nanosheets with thickness of 30–100 nm and the Cu3(MoO4)2(OH)2 hallow spheres, consisting of a large number of nanosheets with thickness of about 40-70 nm. The Cu3Mo2O9 samples that obtained by thermal treatment of lindgrenite retained the original morphologies. Meanwhile, the photoluminescence and magnetic properties of the nanosheet samples showed super paramagnetic behavior at room temperature and in comparison with previous works, Cu3(MoO4)2(OH)2 and Cu3Mo2O9 samples synthesized by the surfactant-assisted hydrothermal method had a very obvious red-shifted PL emission and high intensity.
Yasin Mehdizadeh, Saeed Reza Allahkaram, Mohammad H.mohammad-Ebrahimi, Majid Shamsarjmand,
Volume 22, Issue 4 (12-2025)
Abstract
The present work deals with the corrosion behavior and mechanical properties of a coted AZ31 magnesium alloy through plasma electrolyte oxidation (PEO) coating process in different alkaline electrolytes based on sodium silicate (Si-coating), sodium polyphosphate (P-coating) and sodium aluminate (Al-coating). The scanning electron microscopy (SEM) equipped with the energy dispersive x-ray spectroscopy (EDX) plus x-ray diffraction were recruited to investigate the morphology, chemical composition, and phase structure of coatings, respectively. Microscopic scrutiny revealed that the coating in the phosphate electrolyte was twice as thick and the relative porosity percentage was higher than those formed in the other electrolytes. The phase analysis indicated that the MgO was present as the prevailing phase in the Al-coating and P-coating. However, the dominant phase in the Si-coating was Mg2SiO4. Electrochemical testing was examined in a solution containing 3.5.wt% sodium chloride, showing improvements in corrosion resistance of coated alloys. These investigations confirmed that the corrosion resistance of Si-coating was dramatically higher than others which could be attributed to the presence of the dense and stable Mg2SiO4 phase as well as its relatively low porosity. According to the results of tensile tests, the coated samples had lower tensile strength and elongation than the uncoated one. The tensile strength and elongation diminished upon changing the electrolyte from Al-coating to P-coating, while the yield strength was almost similar. Further analyses indicated that the drop of tensile strength and elongation could be attributed to the presence of cracks and pores in the brittle ceramic PEO coating as stress concentration regions during deformation. Those areas are created due to thermal stress during the coating process and deformation in the elastic stage.
Marzieh Akbari, Fatemeh Dabbagh Kashani, Seyed Mohammad Mirkazemi,
Volume 22, Issue 4 (12-2025)
Abstract
CIGS solar cells are currently very high-efficiency thin-film solar cells. With regard to higher efficiency in solar cells, research is being conducted on the influence of both light scattering and plasmonic resonances due to metallic nano-structures. This article discusses the assessment of the incorporate plasmonic nanostructures on the absorber layer of a 1000 nm CIGS solar cell, in terms of light absorption and device performance. It is noted that decisions on material, size, and surface coverage (Occupied Factor) were important considerations that affected the performance. Opto-electrical assessment was used to investigate absorption, charge-carrier generation, current density-voltage response, power-voltage properties, and total efficiency. Using simulations, we discovered the aluminum nanosphere arrays (200 nm diameter, Occupied Factor 0.64) at the top of the absorber layer yielded the maximum efficiency (26.14%). This was shown by the resonances, and near-field distribution garnered from the nanospheres boost charge carrier generation, diminished recombination losses, and increased charge separation. Collectively, these raised the performance of the CIGS solar cells in this research and suggested hope for moving CIGS and potentially other photovoltaics forward using nanoscale plasmonic resonances.
Mohammad J. Rezaei, Mohammad Sedighi,
Volume 22, Issue 4 (12-2025)
Abstract
The investigation of the mechanical response and microstructural evolution of engineering materials at the micro-scale under macro-scale loading poses a significant challenge in mechanical engineering, particularly in the fields of material forming and materials science. This critical has been addressed using a computational crystal plasticity tool known as DAMASK (Düsseldorf Advanced Material Simulation Kit). DAMASK is a multi-scale computational framework developed for modeling the deformation of crystalline materials by employing the principles of continuum mechanics and crystal plasticity. This software is widely recognized within the scientific community for its high flexibility and capability to simulate complex material behavior under various loading conditions. In this study, the DAMASK code—a finite element crystal plasticity software—was employed to analyze a representative volume element (RVE) containing 1000 grains under tensile loading. By applying a random initial texture to aluminum grade 1050, the microstructural evolution of the material under the specified loading conditions was evaluated. The results indicate the formation of <111> and <100> fiber textures in the (111) crystallographic plane of the FCC-structured material, which are consistent with observations obtained from EBSD experiments.
Vyacheslav Sirota, Sergey Savotchenko, Valeriya Strokova, Daniil Podgornyi, Marina Kovaleva, Sergey V Zaitsev, Аnton S Churikov,
Volume 22, Issue 4 (12-2025)
Abstract
The surface properties of metal-ceramic coatings based on titanium dioxide are described in dependence on the detonation spraying conditions. It is found that such properties as surface roughness, surface thickness and its hydrophobicity can be controlled in the production process by selecting certain values of the technological parameters of the spraying process. The optimal values of the technological parameters of detonation spraying, ensuring maximum hydrophobicity of the produced coatings are determined. The roughness of the coating surface and the coating thickness depend on the speed of the nozzle passage in accordance with the inverse power law. The roughness and the contact angle depend on spray distance in accordance with a parabolic law. New equations are obtained that can be useful for predicting the characteristics of the coating surface, as well as for determining the optimal mode of spraying the coating, ensuring its best hydrophobicity.
Khashayar Zamani, Majid Tavoosi, Ali Ghasemi,
Volume 22, Issue 4 (12-2025)
Abstract
The present work, set out with the aim of studying the effect of in-situ precipitation of TiO2 form Ti3C2Tx MXene phase on the electromagnetic (EM) behavior of Ti3C2/TiO2 composites. In this regard, Ti3C2Tx MXene phase was synthesized using HF acidic etching of Ti3AlC2 MAX phase and the in-situ precipitation of TiO2 phase within Ti3C2 sheets was followed by controlled annealing in temperature range of 500-800 oC for 2 h. The phase and structural characteristics of prepared composites were investigated using X-ray diffraction (XRD), scanning electron microscope (SEM) and differential thermal analysis. The electromagnetic behavior of samples was also analyzed using vector network analyzer (VNA). The results showed that by performing the controlled annealing process of Ti3C2Tx MXene phase, it is possible to in-situ formation of TiO2 phase and form the Ti3C2/TiO2 composites. The electromagnetic behavior of Ti3C2/TiO2 composites is in direct relation with the percentage of TiO2 phase deposited within Ti3C2 sheets during annealing process. The reflection loss (RL) changed from -7.98 to -21.28 dB (within frequency range of 1-18 GHz) with increasing in annealing temperature from 500 to 800 oC as well as increasing the size and percentage of formed TiO2 particles.
Krishna Jyothi N, Keerthi M., Gnana Kiran M., Venkata Kamesh Vinjamuri, Prakash Babu Kanakavalli, Krupakaran R.l, Nandini P.s.v., Rao M.c., D. Madhavi Latha, Mahamuda Sk.,
Volume 22, Issue 4 (12-2025)
Abstract
This research systematically examines the structural, electrical, and optical characteristics of Tamarind Seed Polysaccharide (TSP)--based biopolymer electrolytes that are doped with varying concentrations of sodium iodide (NaI). Composite films were synthesized using the solution cast technique in weight percent ratios of TSP: NaI (100:0, 90:10, 80:20, 70:30) and subsequently characterized employing X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), UV–Vis spectroscopy, and impedance analysis. The XRD analysis indicated that the 80:20 composition displayed the highest degree of amorphousness, which is associated with improved ionic conductivity and reduced crystallite size. The FTIR analysis corroborated the occurrence of complexation between TSP and NaI, while the temperature-dependent conductivity measurements conformed to Arrhenius behaviour, with the 80:20 film achieving the ionic conductivity (1.97x10⁻4 S/cm) and the lowest activation energy (0.69 eV). Optical absorption investigations revealed a decrease in the bandgap from 3.92 (pure TSP) to 2.68 eV (80:20 film). Minimum optical energy bandgaps were achieved for the optimized film. Opto-dielectric investigations further demonstrated that the 80:20 formulation exhibited optimal dielectric permittivity and loss. The results underscore the potential applicability of TSP–NaI biopolymer systems as sustainable, high-performance polymer electrolytes.
Nima Hoseinizadeh, Farzaneh Kiarad, Zahra Kiani, Abolfazl Sadeghi, Azadeh Taherpour, Mehdi Shakibaie,
Volume 22, Issue 4 (12-2025)
Abstract
Glioblastoma multiforme is an aggressive brain tumor with limited therapeutic options. This study evaluated the multifunctional anticancer effects of curcumin-synthesized silver nanoparticles (curcumin-AgNPs) on the U-87 glioblastoma cell line. Curcumin-AgNPs were biosynthesized using curcumin as a reducing and stabilizing agent and characterized by ultraviolet–visible spectroscopy (UV–Vis), dynamic light scattering (DLS), and transmission electron microscopy (TEM). Cytotoxicity was assessed by MTT assay. The mRNA expression of apoptosis- and epithelial–mesenchymal transition (EMT)-related genes was quantified by real-time PCR. DLS and TEM analyses revealed curcumin-AgNPs with sizes of 56.27±4.59 nm and 22±3 nm, respectively. Curcumin-AgNPs reduced U-87 MG cell viability in a dose- and time-dependent manner. Analysis of apoptosis-related genes showed an increased BAX/BCL2L1 ratio. Additionally, FN1 and VIM were downregulated to 0.48- and 0.60-fold, respectively, indicating inhibitory effects on EMT and the metastatic potential of U-87 MG cells. These findings indicated that curcumin-AgNPs exhibit cytotoxic, pro-apoptotic, and EMT-modulating effects in U-87 MG cells, highlighting their potential as a multifunctional nanoplatform for glioblastoma research. Further studies are required to elucidate their underlying mechanisms.
Aicha Kater, Saâd Rahmane, Fatima Djenidi, Hala Nezzal, Nourelhouda Mokrani, Elhachmi Guettaf Temam, Hadjer Barkat, Boutheina Saadi, Brahim Gasmi,
Volume 22, Issue 4 (12-2025)
Abstract
Zinc oxide (ZnO) thin films have garnered significant interest for their applications in optoelectronics and environmental remediation due to their exceptional optical, electrical, and photocatalytic properties. However, the high resistivity and rapid charge recombination of pure ZnO necessitate doping to enhance its performance. In this study, ZnO thin films doped with tin (Sn) and aluminum (Al) were synthesized via a cost-effective pneumatic spray technique. The structural, optical, and morphological properties of the films were systematically characterized using X-ray diffraction (XRD), UV-Vis spectrophotometry, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The results indicate that Sn and Al doping significantly influence ZnO’s crystallinity, bandgap energy, and surface morphology. The optimal crystallite size was obtained for 1 wt.% Sn (37.98 nm) and 5 wt.% Al (48.63 nm), while excessive doping (>3 wt.%) introduced microstrain (10.41 × 10⁻⁴ for Sn and 7.13 × 10⁻⁴ for Al), reducing crystallinity. The optical bandgap decreased from 3.254 eV (pure ZnO) to 3.142 eV (1 wt.% Sn) and 3.152 eV (5 wt.% Al), accompanied by increased Urbach energy (0.34 eV for 5 wt.% Al). The highest optical transmittance (86%) was observed for 3 wt.% Al-doped ZnO. Pure ZnO exhibited the highest photocatalytic efficiency, achieving 85% methylene blue degradation under solar irradiation. Langmuir adsorption modeling revealed that Sn-doped ZnO exhibited the highest adsorption capacity (1.422 mg/g), followed by Al-doped ZnO (0.617 mg/g) and pure ZnO (0.495 mg/g). These findings emphasize the critical role of doping concentration in optimizing ZnO thin films for advanced photocatalytic and optoelectronic applications.
Mohadeseh Karimi, Mohammad Hossein Enayati, Fatemehsadat Sayyedan,
Volume 23, Issue 1 (3-2026)
Abstract
The aim of this study was to optimize the values of current density and carbide concentration in electrodeposition process of Ni-Fe(Si-Ti)C nanocomposite coating on the AISI 304 stainless steel. The optimal current density in each electrolyte was determined using scanning electron microscope (SEM) images and energy-dispersive spectroscopy (EDS) analysis. Corrosion behavior and wear resistance of the optimized coatings were examined by TOEFL polarization test in 3.5 wt.% NaCl solution and ball-on-disk apparatus, respectively. The values of 30 mA/cm2 and 10 mA/cm2 were obtained to be the optimal current densities for electrolytes containing 6 g/L and 12-18 g/L double carbide, respectively. Electrochemical measurements declared that the corrosion rate decreased from 0.0829×10-5 mA/cm2 to 0.0208×10-5 mA/cm2 with increasing the concentration of carbide in the electrolyte from 6 g/L to 18 g/L. Moreover, the friction coefficient of the substrate was found to be significantly greater than that of the coated samples.
Muayad Raheem Hussein, Sabah Hasan Jumaah, Ali N. Majees,
Volume 23, Issue 1 (3-2026)
Abstract
In the current study, titanium dioxide (TiO₂) nanoparticles were synthesized and subsequently combined with chitosan (CS) and silver (Ag) to augment their antimicrobial effectiveness. The synthesized TiO₂, TiO₂-CS, and TiO₂-CS-Ag nanocomposites were subjected to various characterization analyses in order to thoroughly assess their structural, morphological, and compositional attributes. XRD analysis substantiated the phase transition from anatase to rutile consequent to incorporation of chitosan and silver, accompanied by a diminution in nanoparticle dimensions. FTIR spectra corroborated the existence of functional groups linked to chitosan and silver, while FESEM illustrated morphological modifications, notably the emergence of polygonal nanostructures within the TiO₂-CS-Ag composite. The antibacterial efficacy of the synthesized nanocomposites was evaluated against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Although pure TiO₂ demonstrated minimal antibacterial properties, the TiO₂-CS and TiO₂-CS-Ag composites exhibited substantial inhibition zones, with the most pronounced efficacy recorded for the TiO₂-CS-Ag composite attributable to the synergistic interaction between chitosan and silver nanoparticles. BET analysis revealed that the augmented antimicrobial activity was associated with the increased surface area of the TiO₂-CS-Ag nanocomposite.
Zahra Zalnezhad, Morteza Sasani Ghamsari, Hamid Haratizadeh,
Volume 23, Issue 1 (3-2026)
Abstract
Silicon carbide (SiC) is one of the most important silicon-based compounds, owing to its favorable physical, chemical, and biological properties, and is widely employed in various fields such as electronics, chemical industries, and quantum computing. Several methods have been reported for synthesizing SiC nanoparticles, including chemical vapor deposition (CVD), hydrothermal synthesis, carbothermal reduction, and sol–gel processing. Among these, the sol–gel method has attracted significant attention due to its high yield, process controllability, biocompatibility, accessibility of precursors, and ability to produce nanoparticles. In this study, SiC nanosized powders were synthesized through the sol–gel route combined with carbothermal reduction, using tetraethyl orthosilicate (C2H5)4SiO4) and sucrose (C11H22O11) as the silicon and carbon sources, respectively. The silica/sucrose composite was subjected to carbothermal reduction under an argon atmosphere at a pressure of 10 mTorr in a vacuum furnace at 1350°C for 3 h. The structural properties of the synthesized SiC nanopowders were analyzed using X-ray diffraction (XRD), while their optical characteristics were investigated through FTIR, diffuse reflectance spectroscopy (DRS), and photoluminescence (PL). This work demonstrates a greener, lower-temperature route to phase-controlled SiC nanoparticles with optically active vacancy centers.
Moges Tsega Yihunie,
Volume 23, Issue 2 (6-2026)
Abstract
Copper oxide (CuO) nanoparticles (NPs) were synthesized by the sol-gel method, followed by calcination at 600 oC for 2 h. The XRD pattern indicated that the synthesized CuO NPs had a monoclinic structure, with an average crystallite size of 53 nm. The FT-IR spectra showed that surfactant molecules were adsorbed on the surface of the CuO nanoparticles, along with the presence of Cu-O bonding. The TEM analysis revealed rod-like CuO NPs with diameters of about 50 nm and lengths ranging from 150 to 200 nm. The XPS analysis confirmed that copper and oxygen were synthesized as the main components with Cu2+ and O2-oxidation states. The optical band gap of CuO was calculated to be 3.5 eV. The maximum PL emission was recorded at 430 nm for the 365 nm excitation wavelength, and the change in PL intensity and peak shift was calculated as a function of excitation wavelength. The Mie analysis results also showed that when crystallite sizes increased, so did the maximum values of extinction efficiency, scattering efficiency, asymmetry, and scattering matrix. The findings of this study imply that CuO NPs could be a viable choice for a variety of luminous device applications.
Daniela Grigorova, Gyunver Hodjaoglu, Feyzim Hodzhaoglu,
Volume 23, Issue 2 (6-2026)
Abstract
Producing high-purity iron powders with controlled particle morphology is essential for advanced powder metallurgy, additive manufacturing, and functional materials. However, achieving precise morphological control in environmentally benign, additive-free electrolytes remains challenging. This study systematically investigates the galvanostatic electrodeposition of iron powder from sulfate-based electrolytes containing 10.0 and 50.0 g·L⁻¹ Fe²⁺, focusing on the interplay between current density, pH evolution, deposition efficiency, and particle structure. A clear transition from compact, adherent deposits at low current densities to dendritic, easily detachable powders at higher values was observed. SEM analysis revealed well-defined dendritic aggregates at 7 A·dm⁻² (30–80 μm), whereas highly fragmented, porous agglomerates formed at 10 A·dm⁻², accompanied by fine-scale fragmentation driven by intense hydrogen evolution. XRD confirmed pure α-Fe for current densities up to 7 A·dm⁻², while partial oxidation to Fe₃O₄ occurred at 10 A·dm⁻²; EDX mapping further supported this surface oxidation. The deposited mass increased linearly with current density for both Fe²⁺ concentrations, with regression models yielding R² values above 0.96. Current efficiency decreased at high current densities due to enhanced parasitic reactions. Overall, the results demonstrate that galvanostatic electrodeposition in additive-free sulfate media enables controlled synthesis of iron powders, with tunable morphology and phase purity governed primarily by current density and electrolyte composition.
Sumrit Mopoung, Rinlaphat Thanakulwaranon,
Volume 23, Issue 2 (6-2026)
Abstract
Activated charcoals were prepared by activation with 600 W microwave irradiation in combination with pretreatments of tamarind wood derived charcoal in boiling mixtures with NaOH (1 g : 0 g - 1 g: 0.12 g). The samples were characterized by FTIR, XRD, SEM-EDS, and BET, and used for catalytic nitrite c oxidation under air atmosphere in the absence of light at 30°C, pH 6.5, and 120 rpm shanking for improved efficiency. The results show that the percent yields of tamarind wood derived activated charcoals (ACCs) were 88.51% - 94.66 %. The main carbonate compounds of ACCs are present in the materials after activation. Na+ ions and water molecules could be inserted into the graphitic layers during pretreatment and efficiently effected surface cracking of ACCs by 600 W microwave irradiation. The surface cracklings and porosities of ACCs increased with increasing concentration of NaOH from 1 M to 3 M with optimum at 2 M NaOH. The final products are mesopore materials containing macro and meso hole channels. It was found that the nitrite conversions exhibit high reaction rates and are completed within 20 min. The reactions proceed via catalytic oxidations and their rates increase with increasing concentrations of NaOH activation, while nitrite conversions via the disproportionation reaction were inhibited.
Rihab Jabbar, Mohammed Alluaibi, Sara Shahatha, Dhuha Hasan,
Volume 23, Issue 3 (9-2026)
Abstract
This study investigates the effect of sintering temperature on the structural, dielectric and magnetic properties of cobalt ferrite nanoparticles (CoFe₂O₄ NPs) synthesized by the sol–gel method. The samples were sintered at 400°C–1000°C for 2 h and characterized using XRD, FTIR, SEM, AFM, dielectric and VSM measurements. XRD confirmed the formation of a stable cubic spinel structure, with crystallite size increasing from 10.71 to 16.09 nm and porosity decreasing with increasing sintering temperature. SEM and AFM showed progressive grain growth and improved grain connectivity, with the sample at 800°C exhibiting the most uniform morphology before excessive grain growth occurred at 1000°C. The dielectric response showed decreasing real and imaginary permittivity with increasing frequency, while the sample at 800°C exhibited the lowest dielectric loss (tan δ ≈ 2 at 1 kHz). Magnetic measurements revealed ferrimagnetic behavior, with saturation magnetization increasing from 27.5 emu/g at 400°C to 68 emu/g at 1000°C, whereas coercivity reached a maximum of 715 Oe at 800°C. Overall, sintering at 800°C provided the best balance between microstructural uniformity, low dielectric loss and magnetic performance, making it a strong candidate for further evaluation in high-frequency and multifunctional magnetic applications.
