High Energy Ball Milling Technique Research Articles

Enhancing Long Stability of Solid-State Batteries Through High-Energy Ball Milling-Induced Decomposition of Sulfide-Based Electrolyte to Sulfur.

Metal sulfides are increasingly favored as cathode materials in all-solid-state batteries (ASSBs) due to their high energy density, stability, affordability, and conductivity. Metal sulfides often exhibit capacities exceeding their theoretical limits, a phenomenon that remains not fully understood. In this study, it reveals that this phenomenon is primarily due to the sulfur decomposition from sulfide-based electrolyte. By employing the high-energy ball milling (HEBM) technique, the deposition of sulfide-based electrolyte onto sulfur is intentionally promoted, resulting in higher charge capacities compared to the discharge capacities and surpass theoretical limits of metal sulfides. Using chromium sulfide (Cr2S3) as the active material, the sulfur decomposed from sulfide-based electrolyte transforms into lithium sulfide (Li2S) after discharge, resulting in an increased capacity by ≈439.6 mAhg-1 and improved cycling stability. Consequently, it demonstrates a specific capacity surpassing 1200 mAh g-1 with a capacity retention of over 80% after 650 cycles, maintaining cycling stability for more than 1900 cycles and achieving a Coulombic efficiency exceeding 99.9%. This versatile HEBM approach enables the fabrication of ASSBs utilizing various transition metal sulfides, such as molybdenum disulfide (MoS2), niobium disulfide (NbS2), and iron disulfide (FeS2), all exhibiting over theoretical limited capacities and prolonged cycling capabilities.

Innovation in sustainable composite research: Investigating graphene-reinforced MMCs for liquid hydrogen storage tanks in aerospace and space exploration

The demand for lightweight materials in space exploration applications has seen a significant rise. This study presents a novel approach by integrating graphene with Aluminium alloy (AA) 2900 powder, synthesized through High energy ball milling technique. The resulting powder was used to reinforce Aluminium alloy 2195, creating metal matrix composites (MMCs) via squeeze casting. The findings demonstrate that incorporating 0.5 wt % 2D graphene nanoplatelets (2D-Grnp) in AA 2195 achieved density match, enabling homogeneous dispersion, addressing composite casting challenges. Consequently, the AA 2900 alloy embedded with 2D-Grnp facilitated the homogeneous dispersion of reinforcements during the squeeze casting process, yielding MMCs Ideal for potential use in lightweight liquid hydrogen fuel tank structures for launch vehicles. Following T8 heat treatment, the final casted composite plate exhibited significant enhancements in ultimate tensile strength, with a 4.5% increase over monolithic Al 2195-T8, exhibiting nominal reduction in elongation behavior and higher hardness. Additionally, scanning and transmission electron microscopy (SEM, TEM), Small Angle Neutron Scattering (SANS) and Electron Backscatter Diffraction (EBSD) revealed the squeeze casting technique's effectiveness by exhibiting enhanced bonding among homogeneously reinforced 2D-Grnp, T1/θ’ precipitates, and AA 2195.

Multiferroic properties of NiFe2O4-Ba0.7Ca0.3TiO3 nanocomposites

In this report, we present results on the multiferroic properties of four nanocomposite samples of NiFe2O4-Ba0.7Ca0.3TiO3 (NFO/BCTO), which were fabricated through combinations of high-energy ball milling, heat treatment, and spark plasma sintering techniques. Structural analyses revealed that these samples simultaneously contain two phases of nano-sized NiFe2O4 (NFO) and Ba0.7Ca0.3TiO3 (BCTO) crystals. The addition of NFO into the BCTO-host did not alter the crystal structure but significantly improved the multiferroic characteristics compared to pure BCTO. Furthermore, variations in saturation magnetization (M s) and coercivity (H c) were investigated as a function of temperature. The results showed that Ms increased gradually with the concentration of NFO. In terms of temperature dependence, M s(T) data deviated from the Bloch’s law with an exponent coefficient α changing in the range of 1.8–1.9, decreasing gradually as the NFO concentration increased. Meanwhile, H c decreased gradually as the NFO concentration increased and followed the Kneller’s law in terms of temperature dependence.

Highly reversible Mg-containing multicomponent high-entropy alloys for electrochemical hydrogen storage applications

Magnesium containing high entropy alloys have gained attention recently as a potential material for hydrogen storage applications. In this work, five non-equiatomic compositions of MgTiZrNiAl HEAs were synthesized using a high-energy ball milling technique and electrochemically characterized for hydrogen storage performance. The concentrations of Mg and other constituent alloying elements are critical to achieving good storage capacity and other hydrogen storage properties. Interestingly, higher Mg atomic percent (40–50 at%) in the HEA matrix showed high gravimetric capacity, and increasing the constituent element like Ni has significantly enhanced the overall storage capacity, kinetics, and thermodynamic properties. Overall, 1 wt% of hydrogen was electrochemically stored with high reversibility, improved hydrogen diffusion coefficient, and anticorrosion ability.

Evolution of Morphology, Particle Size and Oxidation Resistance of Recycled Ti-6Al-4V Powders Prepared by Planetary Ball Milling

AbstractPlanetary ball milling is a high-energy ball milling technique that is widely used for the synthesis of alloy and composite powders with micrometer or nanometer particle sizes. The effect of process control agent (PCA) content (wt%) and milling time on the morphology, particle size and distribution, crystallite structure, apparent density and oxidation resistance of recycled T-6Al-4V alloy powders from lathe chips is investigated in this study. To investigate the effect of the PCA on the properties of the Ti-6Al-4V alloy particles, methanol is used as the PCA in various amounts of 0.5, 1 and 2 wt%. The milling is carried out using 20:1 of ball-to-powder ratio (BPR) and 400 rpm of milling speed. A morphological change from scrap form to flake-like shape, from flake-like morphology to irregular and semispherical shape and finally from semispherical form to spherical morphology is observed with increase in milling time for all PCA ratios. The results showed that the average particle sizes (D50) are 20, 18.1 and 21.8 μm after milling of 360 min with 0.5 wt%, 1 wt% and 2 wt% PCA, respectively. Results show that the most suitable recycled Ti-6Al-4V powders for powder-based manufacturing techniques are produced between 180 and 360 min of milling with 2 wt% PCA.

Synergistic effect of Al2O3-decorated reduced graphene oxide on microstructure and mechanical properties of 6061 aluminium alloy

In this study, Al6061 alloy matrix composites reinforced Al2O3-decorated reduced graphene oxide (Al2O3/RGO) with 0.1, 0.3 and 0.5 weight present (wt%) were successfully fabricated using high energy ball milling and hot extrusion techniques. The microstructures of these Al2O3/RGO/Al6061 aluminum matrix composites (Al MMCs) were characterized. The results showed that Al2O3/RGO were uniformly distributed within the Al6061 matrix and tightly bonded to the matrix. Al2O3 encapsulation on RGO surface would prevent the formation of Al4C3 brittle phase in matrix, ensuring that there was no reaction between the reinforcement and the matrix Al6061. Tensile strength and Vickers hardness tests demonstrated that the mechanical properties of Al MMCs significantly increased with addition of Al2O3/RGOs. Remarkably, Al MMCs with 0.1 wt% reinforcement showed tensile yield and tensile strengths of 270 MPa and 286 MPa, respectively, which were 49% and 43% higher than those of pure Al6061 prepared using the same process. Furthermore, the 0.1 wt% Al2O3/RGO composite also showed the best plastic deformation capability in considering of the strength.

Suppressing the thermal conductivity to enhance the thermoelectric performance of SnSe2 using the high-energy ball milling in a pressurised N2 atmosphere

Two-dimensional (2D) layered dichalcogenides possess excellent thermoelectric (TE) properties. Among them, tin diselenide (SnSe2) exhibits n-type semiconducting properties with attractive TE performance near room temperature (RT). However, its high thermal conductivity and relatively low electrical conductivity have limited its TE performance for practical applications. In this study, we significantly suppressed the thermal conductivity and enhanced the TE performance of 2D layered SnSe2 polycrystalline structures by reducing the particle size to the nano-scale using the high-energy ball milling (BM) technique in a pressurised N2 atmosphere. The particle size was reduced from ∼2 μm to 100 nm after 15 h of BM. TE results of a highly pressed compact leg made from the TE-optimised BM sample (e.g. 7 h) showed that at RT, the electrical conductivity increased by a factor of 9, whereas the Seebeck coefficient was reduced by only 40%. Consequently, the power factor increased from 12 to 42 μW/m·K2. In addition, the thermal conductivity decreased from 5.72 to 0.40 W/m·K, resulting in a significant increase in the figure of merit by a factor of 40 times higher than that of the non-BM SnSe2 leg. This study also demonstrated power generation using single-leg modules made from these structures at ΔT values above and below RT. The TE power generation of the BM module was found to be much higher than that of the non-BM module, particularly below RT. The 7-h BM module generated 2600 nW at ΔT = 45 K above RT, but when the same ΔT was applied below RT, the generated power reached 8000 nW. This enhancement in power generation below RT is remarkable, suggesting that the BM SnSe2 compact may be useful for generating measurable TE power in cold environments.

Nitrogen-functionalized catalyst synthesized using spent coffee ground biochar-cobalt hybrid for oxygen reduction reaction via pyrolysis and ball-milling

In this work, oxygen reduction reaction (ORR) catalysts were developed from a precursor of spent coffee ground-based biochar. Nitrogen doping was achieved via urea addition preceding a pyrolysis synthesis process, yielding nitrogen-doped biochar (NDB). Cobalt was deposited onto the NDB surface using a non-conventional ball-milling procedure. The microstructure of the synthesized samples was studied through Scanning Electron Microscopy (SEM), where a rather distorted surface, highlighted by prominent wrinkles (which doubled the surface area at 50.58 m2/g), was shown for nitrogen-doped samples. Moreover, the high energy ball-milling technique shows an almost perfect coverage of cobalt nanoparticles on the biochar surface through SEM/EDS and Raman results. Additionally, electrochemical testing was conducted using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Cyclic voltammetry measurements conducted under nitrogen (inert) and oxygen-saturated alkaline solution (0.1 M KOH) conditions showed that nitrogen doping enhances the oxygen reduction reaction current (-1 vs -0.59 mA.cm−1 at -0.3 V vs Hg/HgO) and slightly reduces the onset potential compared to pristine biochar. Depositing cobalt onto the NDB surface had a minor adverse effect on the onset potential, but significantly increased the oxygen reduction reaction current, reaching a value of -2.09 mA.cm−2 at -0.3 V vs Hg/HgO. All catalysts were compared to a commercial carbon supported platinum catalyst (Pt10%C) to showcase the potential room of improvement for the developed catalysts.

Investigation on electrochemical corrosion behavior and mechanical properties of Fe-nano particles produced by high-energy ball milling technique

Abstract This study focuses on converting iron particles from grinding sludge, after removing impurities, into Fe-nanoparticles using high-energy ball billing. The goal is to examine the corrosion behaviors and mechanical properties of these Fe-nanoparticles. Nanostructured Fe-powder was synthesized through a process involving 10 h of high-energy ball milling, followed by conventional hot pressing and sintering. Structural and microstructural properties were thoroughly examined using techniques such as X-ray diffraction (XRD), optical microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and elemental diffraction spectroscopy. Upon sintering, SEM and TEM analyses unveiled the formation of a nanostructured alloy within the samples. Notably, the milled sample exhibited high hardness value, measuring at 155 HV. However, it is noteworthy that the un-milled sample demonstrated superior compression strength compared to its milled counterpart. Furthermore, the corrosion behavior of the samples was evaluated through electrochemical corrosion studies. Interestingly, the sample subjected to 10 h of milling (coin number 5) displayed a significantly lower corrosion rate, measuring at 1.3921 mm/year, suggesting enhanced corrosion resistance attributed to the nano structuring process.

Mechanically robust and conductive Ti5Te4/P@C composite materials as promising lithium-ion battery anodes

An urgent need has emerged to develop lithium-ion battery anodes that exhibit high reversible capacity and rate performance surpassing carbonaceous materials. Si-based composites have been investigated extensively. However, in this study, we explored another potential alloy anode consisting of Te and phosphorus without Si. Herein, we present a novel composite material, Ti5Te4/P@C, as an anode for lithium-ion batteries (LIBs). Tellurium, which exhibits good electrical conductivity and high volumetric capacity, and red phosphorus, which exhibits high theoretical capacity, were selected as potential anode materials. To overcome the common drawbacks of the two materials, including the vigorous expansion of volume, electrochemically inactive materials, such as titanium and carbon, were introduced as matrix buffers. Te, Ti, red phosphorus, and C were synthesized using a three-step high energy ball milling (HEBM) technique, that is, stepwise synthesis of (1) Ti and Te, (2) red phosphorus, and (3) carbon. The developed Ti5Te4/P@C composites revealed that the introduction of red P led to the generation of additional pure Te in the Ti5Te4/P@C composites, which was owing to the different binding interactions between Ti, Te, and red P, as confirmed by DFT calculations. Among the developed Ti5Te4/P@C anodes, Ti5Te4/P(30 wt%)@C exhibited outstanding cyclability and high rate performance (440 mAh g−1 at 300 mA g−1 after 500 cycles). To confirm the electrochemical responses and Li+ ion diffusion mechanisms, CV and GITT analyses were performed. Based on the electrochemical characteristics, the superior electrochemical performance of the Ti5Te4/P@C anodes can be ascribed to the well-defined composite structure, including the high electrical conductivity of Te, high theoretical capacity of red P, and effective buffering agents of Ti as a mechanical supporter and conductive C, which enable a pseudocapacitive response, providing better reversibility. Therefore, the Ti5Te4/P@C composite materials are viable anodes for high-performance LIBs.

Structural characteristics of Zn-MOFs and derived zinc oxide by X-ray diffraction peak analysis fabricated by mechanical and hydrothermal methods

In this work, the Zn based MOFs were synthesized from cyanoguanidine and zinc acetate source precursors via two hydrothermal methods and high energy ball milling technique and also the free salt and bimetallic samples have been synthesized. Then, the fabricated Zn-MOFs were heat for calcination at 550 °C for 110 min. The synthesized nanostructures were examined by XRD, SEM and FTIR analysis to gain insight about structure, morphology and functional groups properties. The results confirm that it is possible to prepare Zn MOFs using high energy ball milling methods. Besides, the fabricated MOF and complex structures can be converted to porous zinc oxide (ZnO) by a simple thermal annealing in air. Then, the line broadening of ZnO from mechanochemical and hydrothermal methods was showed due to the small crystallite size and lattice strain. The broadening was studied by the Scherrer formula and Williamson Hall (UDM, USDM, UDEDM) and Size-strain plot techniques. In addition, undesirable phases may affect the synthesized part during thermal cycles. We demonstrate the potential of using high-energy X-ray diffraction for detailed analysis of minority phases in ZnO-derived components.

Nano casein-pectin complex: exploring physicochemical, organoleptic properties, and LAB viability in skimmed milk and low-fat yoghurt.

Protein complexes with a nutritional value, heat stability, and gelling properties with no negative impact on culture viability have promising application prospects in the fermentation industry. The aim of the study was to investigate the possibility of applying physical modification seeking high-protein-fortified yoghurt production using the nano casein-pectin NCP complex as an active colloidal system with enhanced structural and thermal properties and monitor the quality properties of the physicochemical, heat stability, rheological, starter culture viability and sensory evaluation of fortified products comparing with the plain control throughout the cold storage. High-energy ball milling (HEBM) technique was used to produce nanoparticles of casein powder and smaller particles of pectin individually, and particle size and zeta potential was assessed. Deferent Nano casein-pectin (NCP) complex formulations were prepared, their physicochemical properties were assessed including protein quality via Amino Acid Analyzer (AAA), viscosity, thermogravimetric analysis (TGA), and then used in fortification of skimmed milk and low-fat yoghurt to monitor the fortification effects. The particle sizes showed to be ≈166 nm and 602.6 nm for nano-casein and pectin, respectively. Milk fortification with the NCP complex has significantly increased the nutritional value represented in increased protein content (7.19 g/100 g in NCP5); Ca, P, and S content (2,193.11, 481.21, and 313.77 ppm); and amino acid content with first limiting amino acids; histidine (0.89 mg/g), methionine (0.89 mg/g), and low content of hydrophobic amino acids (HAAs) may cause aggregation. NPC fortification enhanced physicochemical properties announced in enhanced viscosity (62. mP.s in NCP5) and heat stability (up to 200°C) compared with control skimmed milk (SM). NCP yoghurt fortification significantly increased protein content to 11 mg/100 g in T5, enhanced viscosity to 48.44 mP.s in T3, decreased syneresis to 16% in T5, and enhanced LAB viability which was translated in preferable sensorial properties. Applying fortification with nanoparticles of the casein-pectin (NCP) complex balanced the amino acid content and improved physicochemical, rheological, nutritional, and sensorial properties and LAB viability, which can be recommended further in functional food applications.

The Analysis of the Application of Using Nanoceramic Oxides in Fire-resistant Coatings

The increased demand for enhanced fire safety in various industries has spurred interest in the properties and applications of nanoceramic oxide materials. This paper provides a thorough examination of the fundamental attributes of nanoceramic oxides, showcasing their exceptional temperature, corrosion, and wear resistance. The paper discusses synthesis methods like evaporation condensation, high-energy mechanical ball milling, and both vapor and liquid phase chemical techniques. The paper further explicates the underlying mechanisms that enable fire-resistant coatings to retard flames, highlighting thermal insulation, intumescence, and more. Of significance is the potential of nanoceramic oxides to augment the performance of these coatings, evidenced by applications like tunnel fire retardant coatings and steel structure coatings that integrate materials such as Mg (OH)2, nano-SiO2, and TiO2. While challenges in raw material sourcing, eco-friendliness, production, and expertise arise, solutions are proposed. Conclusively, the study underscores the transformative potential of nanoceramic oxides in the realm of fire-resistant coatings, pushing boundaries in fire safety across sectors.

Structural, vibrational and magnetic properties of heat treated CuFe2O4 nanoparticles prepared by two different synthesis routes

The present study employed co-precipitation and high-energy ball milling techniques to synthesize nanoparticles of copper ferrite. Subsequently, the powders underwent air annealing at three distinct temperatures, namely 600 °C, 800 °C, and 1000 °C, for a duration of 3 h. The structural and magnetic properties of the generated compositions were assessed and examined by a range of techniques, including as X-ray diffraction (XRD), infrared (IR) spectroscopy, and vibrating sample magnetometer (VSM). Based on X-ray diffraction examinations, it has been observed that the co-precipitation process results in the production of copper ferrite nanoparticles of smaller size compared to those obtained using the milling procedure. The infrared absorption spectra demonstrated that the enhancement of the annealing temperature resulted in an augmentation of the structural integrity of milled copper ferrite. The results of magnetic investigations conducted at ambient temperature indicate that increasing the annealing temperature resulted in an enhancement of saturation magnetization. The copper ferrite material, which was synthesized using co-precipitation and subsequently subjected to annealing at a temperature of 1000 °C, had the most minimal coercivity value of 138 G and remanence value of 5.26 emu/g. In the context of high-density data storage devices, there is a strong preference for lower coercivity and remanence characteristics. It has been observed that the enhancement of structural and magnetic characteristics requires annealing at elevated temperatures.

Enhancing Thermoelectric Performance in P-Type Sb2Te3-Based Compounds Through Nb─Ag Co-Doping with Donor-Like Effect.

P-type Sb2Te3 has been recognized as a potential thermoelectric material for applications in low-medium temperature ranges. However, its inherent high carrier concentration and lattice thermal conductivity led to a relatively low ZT value, particularly around room temperature. This study addresses these limitations by leveraging high-energy ball milling and rapid hot-pressing techniques to substantially enhance the Seebeck coefficient and power factor of Sb2Te3, yielding a remarkable ZT value of 0.55 at 323K due to the donor-like effect. Furthermore, the incorporation of Nb─Ag co-doping increases hole concentration, effectively suppressing intrinsic excitations ≈548K while maintaining the favorable power factor. Simultaneously, the lattice thermal conductivity can be significantly reduced upon doping. As a result, the ZT values of Sb2Te3-based materials attain an impressive range of 0.5-0.6 at 323K, representing an almost 100% improvement compared to previous research endeavors. Finally, the ZT value of Sb1.97Nb0.03Ag0.005Te3 escalates to 0.92 at 548K with a record average ZT value (ZTavg) of 0.75 within the temperature range of 323-573K. These achievements hold promising implications for advancing the viability of V-VI commercialized materials for low-medium temperature application.

Silicon infused Molybedenum di-selinide (MoSe2) nanosheets for enhanced hydrogen evolution reaction (HER) and lithium-ion battery (LIB) applications

The systematized design of two-dimensional (2D) nanocatalysts for sensible energy-efficient reactions is quite a puzzling prospective aspect in energy-related applications. In this current work, we used a top-down strategy to synthesize silicon (Si) nanoparticles using a high-energy mechanical ball milling technique. In hydrothermal reaction, these Si nanoparticles were introduced into the 2D MoSe2 matrix sequence based on varying the percentages of silicon (0–15%) vs Selinium content. The high crystalline phases of the synthesized 10% Si:MoSe2 exhibited the sheet-like morphology and silicon inserted layered structure. The pristine MoSe2@CC & Si:MoSe2@CC electrodes were prepared by tape casting method. During HER reaction, the miniscule insertion of Si into MoSe2 matrix amplified the current density until 10% addition and moved the reduction curves towards lower onset overpotential (76.23 mV) in addition to the significant Tafel value (112.3 mV/decade). The potential of the better performed electrode in HER was explored as an anode for Lithium-ion battery (LIB) applications. The electrode delivered a discharge capacity of 406.7 mAh g−1 at a current density of 100 mA/g after 100 charge-discharge cycles. Furthermore, the rationally constructed bifunctional electrode (Si:MoSe2@CC) showed strong physicochemical stability, which can be used in future sustainable energy generation and storage devices.

Production of reduced graphene oxide from activated rice husk charcoal using a high-energy ball milling method

Production of high-quality graphene at a commercial scale with low cost remains challenging. Thus, we used a high-energy ball milling approach to make reduced graphene oxide (rGO) from activated rice husk charcoal as an enriched carbon source. The as-produced rGO samples were characterized to determine the effect of various milling times (0, 50, 100, 150, and 200 min) on their structure, morphology, specific surface area, pores volume, and size distribution. The variation in the ball milling times was found to introduce the structural defects and remove the oxygen functional groups, thus improving the overall characteristics of the obtained rGO. The wrinkle sheet-like structures of rGO evolved into numerous paper balls-like transparent rumple morphologies due to the milling process-enabled compression mechanism. In addition, due to the increase of milling times, the amount of carbon in rGO was increased to 89.9 atomic%, and oxygen was reduced to 9.3 atomic%, wherein the thermal agitation-mediated collisions of particles played a significant role. The specific surface area (121.483 m2 g−1) and pore volume (0.133 cm3 g−1) of rGO prepared at a milling time of 50 min were observed to be optimum. It was asserted that a high-energy ball milling technique with controlled milling times could help produce high-quality rGO from activated rice husk charcoal at low cost, leading to the development of sustainable and environmentally friendly material required for diverse applications.

Novel slag/natural rubber composite as flexible material for protecting workers against radiation hazards

This work is an attempt to employ the electric arc furnace (EAF) slag as a by-product material to develop an alternative and environmentally friendly material for gamma-radiation protection applications such as in medical and industrial areas. For this purpose, different concentrations of micro-sized EAF slag (0, 20, 40, 60, 80, 100, 500, and 800 phr) were incorporated as fillers in the natural rubber (NR) matrix to produce the shielding composites. In addition, nano-sized EAF slag particles were prepared by using a high-energy ball milling technique to investigate the effect of particle size on the gamma-radiation shielding properties. The synthesized micro and nano EAF/NR composites were tested as protective materials against gamma-radiation by employing NaI(Tl) scintillation detector and standard radioactive point sources (152Eu, 137Cs, 133Ba, and 60Co). Different shielding parameters such as linear and mass attenuation coefficient, half value layer (HVL), tenth value layer, mean free path, effective atomic number (Zeff), and effective electron density (Neff) were determined to assess the radiation shielding capability of the EAF/NR composites. Furthermore, equivalent atomic number (Zeq) and the exposure buildup factor values for photon energy in the range from 0.015 to 15 MeV were also computed by Geometric Progression method. The experimental results of micro EAF/NR composites showed that at 121.78 keV, EAF0 composite (without EAF slag content) had the lowest μ value of 0.1695 cm−1, while the EAF800 composite (which was loaded with 800 phr of micro EAF slag) had the highest μ value of 0.2939 cm−1 at the same energy, which in turn decreases the HVL from 4.09 to 2.36 cm, respectively. Therefore, increasing the filler weight fractions of EAF slag in the NR matrix, increases the shielding properties of the composites. Moreover, the NR composite reinforced with 800 phr of nano EAF slag has better gamma-radiation shielding efficiency compared to that filled with 800 phr of micro EAF slag. The success of this work was to prepare a flexible, lightweight, low-cost, and lead-free material with better shielding capability.

Development of CI/BFO nanocomposite for efficient microwave absorption in low frequency range of L, S, C, and X – bands

The electronic industry's rapid progress demands highly efficient microwave absorbers with low coating thickness, broad bandwidth, and simple manufacturing. However, achieving all these properties together remains challenging, especially for low-frequency ranges. In this study, a carbonyl iron/barium hexaferrite (CI/BFO) nanocomposite was prepared via facile high-energy ball milling technique, resulting in excellent microwave absorption in L, S, C, and X-bands. The modified morphology of the CI/BFO nanocomposite significantly enhanced the microwave absorption bandwidth. For a 15 h milled sample with 10 wt% of BFO nanoparticles, an effective broad bandwidth (RL < − 10 dB) of 9.15 GHz in 1.9 – 11.05 GHz frequency range was obtained with a low coating thickness of 2.5 mm. An advanced electromagnetic technique utilizing Genetic Algorithm (GA) for designing triple-layer microwave absorbers was employed to improve absorption bandwidth further and decrease layer coating thickness. The optimized design of triple-layer microwave absorber showed an impressive effective bandwidth of 15.12 GHz, covering 2.88 – 18 GHz frequency range while maintaining an overall coating thickness of only 1.77 mm. The developed CI/BFO nanocomposite showcased remarkable ability to absorb microwaves across a wide frequency range due to various absorption mechanisms like eddy currents, conduction, electron hopping, and multiple interfacial polarization, making it highly suitable for ultra-broadband microwave absorption in practical applications.

Frequency and temperature-dependence ZnO based fractional order capacitor using machine learning

This paper investigates the fractional order behavior of ZnO ceramics at different frequencies. ZnO ceramic was prepared by high energy ball milling technique (HEBM) sintered at 1300 °C to study the frequency response properties. The frequency response properties (impedance and phase angles) were examined by analyzing through impedance analyzer (100 Hz - 1 MHz). Constant phase angles (84 °-88 °) were obtained at low temperature ranges (25 °C-125 °C). The structural and morphological composition of the ZnO ceramic was investigated using X-ray diffraction techniques and FESEM. Raman spectrum was studied to understand the different modes of ZnO ceramics. Machine learning (polynomial regression) models were trained on a dataset of 1280 experimental values to accurately predict the relationship between frequency and temperature with respect to impedance and phase values of the ZnO ceramic FOC. The predicted impedance values were found to be in good agreement (R2 ∼ 0.98, MSE ∼ 0.0711) with the experimental results. Impedance values were also predicted beyond the experimental frequency range (at 50 Hz and 2 MHz) for different temperatures (25°C - 500°C) and for low temperatures (10 °C, 15 °C and 20 °C) within the frequency range (100 Hz - 1 MHz).