Saturation Magnetization Value Research Articles

Structural, Spectral, Dielectric, and Magnetic Properties of Gd3+ Substituted Y-type Barium Hexaferrites

Co-precipitation method is used to prepare Mn2Ba2GdxFe12-xO22 (0.00, 0.05, 0.10, 0.15, 0.20, and 0.25) Y-type hexaferrites. X-ray diffraction patterns reviled that prepared samples have single phase. The lattice parameters of ‘a’ and ‘c’ increases from 5.87 Å to 5.89 Å and 43.50 Å to 43.68 Å with the incorporation of Gd3+ (Gadolinium), respectively. Samples crystallite sizes were in the 88.8-201 nm range. The spectrum of FTIR explains Fe-O vibrational bands, which signifies the formation of Y-type hexaferrites. The maximum quality factor ‘Q’ value is obtained at 2 GHz. The maximum Q value at high frequency suggests the potential uses of prepared samples for multilayered chip inductors operating at high frequencies. A reduction in the values of saturation magnetization (Ms), coercivity (Hc) as well as in remanence (Mr) were observed in 32.0-10.2 emu/g, 19.30-5.41 emu/g, and 3084.60-1071.3 Oe range respectively. The decrement in the squareness ratio was also found in the range of 0.594-0.529. The values of squareness ratios greater than 0.5 specify that the prepared materials have a sole magnetic domain. Due to the high coercivity of the prepared materials, these could be used in devices that use high frequencies and perpendicular recording mediums.

Pyrolytic carbon/Cloisite 30B/ZnFe2O4 as reclaimable magnetic nanocomposite for methylene blue decontamination

This study prepared a new magnetic nanocomposite of Cloisite 30B and pyrolytic carbon (PC). Its ability as an efficient adsorbent was studied to remove MB dye. The results of the physical-chemical properties showed that the desired absorbents were synthesized and modified PC using ZnFe2O4 and Cloisite 30B, improving their properties. The specific surface area of PC/Cloisite 30B/ZnFe2O4 (59.66 m2/g) was higher compared to PC (2.51 m2/g) and PC/ZnFe2O4 (37.66 m2/g). The magnetic saturation values of PC/ZnFe2O4 and PC/Cloisite 30B/ZnFe2O4 were 9.19 and 6.36emu/g, respectively. The maximum dye removal using PC/Cloisite 30B/ZnFe2O4 (99.08%) was determined at pH=10, adsorbent dose of 1g/L, time of 50min, temperature of 25 °C, and MB concentration 10mg/L, respectively. The adsorption followed the pseudo-secondary-order model processes kinetic behavior. The adsorption process of MB dye using the desired absorbents was exothermic and spontaneous. The maximum removal capacity for PC, Cloisite 30B, and PC/ZnFe2O4 samples was determined to be 18.48, 28.49, and 43.47mg/g, respectively, which shows the benefits of PC sample modification. Also, the PC/ZnFe2O4 and PC/Cloisite 30B/ZnFe2O4 samples can be reused in more than 5 and 7 steps, respectively, which shows their stability in adsorbing MB dye.

Marine-derived magnetic nanocatalyst in sustainable ultrasound-assisted synthesis of 2,3-diphenyl-2,3-Dihydroquinazolin-4(1H)-One derivatives

This research presents a sustainable approach to fabricate iron oxide nanoparticles by employing phytochemicals derived from marine grass extract as both reducing and stabilizing agents. Formation of magnetic nanoparticles (MNPs) initially confirmed by ultraviolet–visible spectroscopy (UV–vis) showing absorption peak at 370 nm. X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques unveiled magnetic iron oxide NPs with a rod shape, an average size of 21 nm, and an inverse spinel crystal structure. The participation of organic compounds in the production and stabilization of MNPs was evidenced through Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). A vibrating sample magnetometer (VSM) demonstrated the magnetic properties of iron oxide NPs showing a saturation magnetization value of 21.46 emu/g. The catalytic efficiency of these marine-assisted MNPs was evaluated in a one-pot three-component reaction involving isatoic anhydride, aromatic aldehydes, and amines under ultrasonic conditions. Under optimal conditions, a low dose of 1.5 mg of biobased magnetite nanoparticles yielded dihydroquinazolin-4(1H)-One products with up to 95 % efficiency in a brief duration of 15 min at an ultrasonic power intensity of 130 W. Different directing groups were investigated, and control experiments were carried out to enhance the understanding of the reaction mechanism. The obtained results highlight the synergistic effect of marine grass-mediated magnetic nanocatalysts combined with ultrasonic-assisted synthesis in developing sustainable green methodologies in organic synthesis.

Synthesis of Copper-Doped Metal Nanoferrites for Efficient Removal of Pharmaceutical Wastewater Pollutants in Membrane Bioreactor System

Pharmaceuticals present in the aquatic environment can poison aquatic species and humans through drinking water and cause harmful bacteria to become resistant. The role of transition metal doped metal nanoferrites for the enhanced efficiency of degradation process is widely achieved. In this work, copper doped magnesium ferrite (Cu-MgFe2O4) and copper doped zinc ferrite (Cu-ZnFe2O4) nanoparticles were synthesized using a sol-gel method. X-ray diffraction (XRD) analysis confirmed the formation of the spinel structure for both samples, with crystal sizes of 16.72 nm and 59.05 nm, respectively. The magnetic properties of the samples were studied using a vibrating sample magnetometer (VSM), which revealed that the addition of Cu2+ ions has a significant impact on the magnetic properties of the nanoparticles. The saturation magnetisation (Ms), retentivity (Mr) and coercivity value (Hc) for the Cu-MgFe2O4 sample were found to be 0.18453 emu, 39.584 × 10-3 emu and 139.61 Oe, respectively, while for the Cu-ZnFe2O4 sample, the values were 0.21271 emu, 71.022 × 10-3 emu and 285.91 Oe, respectively. The impact of copper doped nanoferrites on pollutant removal from pharmaceutical wastewater using the membrane Bioreactor (MBR) system has also been accomplished. The results demonstrated the effectiveness of ferrites in reducing concentrations of heavy metals, including lead and cadmium, within acceptable ranges for inland surface water and public sewers. Furthermore, the MBR system with ferrites exhibited efficient removal of fluoride, sulphide and radioactivity, ensuring compliance with the specified standards. Although the study exhibited the potential of ferrites in pollutants removal, further optimization is necessary to achieve complete compliance with water quality standards.

Structural, Magnetic and Electrochemical Properties of Nickel Manganese Ferrite (NixMn1-xFe2O4) Nanoparticles Prepared via Coprecipitation Method

In current work, the co-precipitation approach was effectively used to synthesize NixMn1-xFe2O4 nanoparticles. Thermal stability of the nickel manganese ferrite nanoparticle was observed at temperatures above 390 ºC by TG/DTA analysis. XRD investigation revealed the cubic structure of the synthesized NixMn1-xFe2O4 nanoparticles. The average crystallite size of synthesized nanoparticles determined via Scherrer’s equation, increases linearly with calcination temperature and nickel concentration. The FTIR spectra showed the existence of stretching vibrations of metal oxide, which are ascribed to the formation of nickel manganese ferrite nanoparticles. The surface morphology of NixMn1-xFe2O4 nanoparticles, as observed using FESEM, exhibited a spherical shape. The EDX spectrum indicates the occurrence of Ni, Fe, Mn and O in the synthesized nickel manganese ferrite nanoparticles. The average size of the crystallites, as determined by XRD, closely matches the analysis conducted using HRTEM. The magnetic properties of NixMn1-xFe2O4 nanoparticles were analyzed using VSM. Nickel manganese ferrite nanoparticles exhibit increasing saturation magnetization and coercivity values as nickel concentration increases, indicating soft ferrimagnetic properties and making it appropriate for high-density recording devices. The cyclic voltammetry investigation of Ni0.7Mn0.3Fe2O4 sample, calcinated at 600 ºC, reveals a significant specific capacitance of 590 F g–1 at a scan rate of 2 mV s–1, suggesting its potential use in supercapacitors.

Water purification and biological efficacy of green synthesized Co/Zn-Doped α-Fe2O3 nanoparticles

In the present study, Co/Zn doped α-Fe2O3 (Hematite) nanoparticles (NPs) were synthesized using polyvinylpyrrolidone (PVP) and Azadirachta indica (AI) leaves aqueous extract. The analytical techniques including XRD, UV, SEM, EDX, VSM, Raman, and FTIR, we were able to identify and characterize the structural, morphological and magnetic attributes of the synthesized NPs. The findings demonstrated that the synthesized NPs exhibit homogeneous spherical shapes with particle sizes ranging from 8.64 to 15.32 nm. The NPs have rhombohedral crystal lattices, with crystallite sizes of 23.25 nm for chemically synthesized doped α-Fe2O3 NPs and 12.52 nm for those synthesized using green methods. The magnetic study has shown that the saturation magnetization (Ms) value of NPs, which ranges from 36 to 45 emu/g at ambient temperature, exhibits superparamagnetic properties (300 K). The treatment of industrial wastewater and its reuse for agricultural purposes are the subjects of the current study. Different concentrations of doped α-Fe2O3 NPs were used as photocatalysts to degrade dyes in a bioreactor under UV light in a heterogeneous mixture. The degradation rates achieved were 96.42 % for Congo Red (CR) and 98.36 % for Eosin Yellow (EY). DPPH assays were conducted to evaluate the antioxidant activity of the synthesized doped α-Fe2O3 NPs. The percentage inhibition of DPPH radicals ranged from 71.13 % to 90.35 %. Our findings indicate that AI leaf extract holds promise as a valuable resource for the development of bioactive compounds and environmentally friendly approaches to synthesizing green NPs. This is primarily attributed to the increased accessibility of bioactive components with potent antioxidant properties. The combination of these benefits provides opportunities for novel uses in environmental cleanup, biological applications, and energy conversion.

Structural, optical and magnetic characteristics of Mg2+- doped (Ba0.94Sr0.06)(Fe0.80Al0.20-xMgx)O3-ẟ (x = 0–0.20) oxides

Perovskite-type ABO3 oxides have attracted immense attention in recent technologies e.g., gas sensors, solar cells, fuel cells, oxygen-permeable membranes, etc. An attempt has been made here to synthesize (Ba0.94Sr0.06)(Fe0.80Al0.20-xMgx)O3-ẟ (x = 0–0.20) oxides using sol-gel method and characterized with regards to phase, Raman and magnetic properties. X-ray diffraction-cum-Rietveld refinement shows the structural transformation from cubic (Pm3m) to hexagonal (P63/mmc) via cubic (Pm3m) + rhombohedral (R3c) and increase of cubic lattice parameter ac = 4.0369–4.1296 Å with magnesium. FT-IR spectra exhibit different vibrational bands at 548, 555, 638, 667, and 692 cm−1, representing the metal-oxygen (M-O-M) bond vibrations (M - Fe, Mg, Al), deformation of MO6 octahedral, and internal changes in bond lengths. No Raman band was appeared for cubic phase with x=0–0.10. Bands between ∼ 250–450 cm−1 assign the tilting, rotation, and asymmetric bending vibrations of Fe – O, Mg – O and Al – O bonds and asymmetric bending mode of (Fe/Mg/Al)O6 octahedra. Oxygen bending vibration, anti-stretching mode and presence of oxygen vacancies lie in the bands of range ∼498–656 cm−1. Maximum coercivity (Hc ∼ 1081 Oe) and remanent magnetization (Mr ∼ 0.033 emu/g) have been observed for x = 0 and found similar variation with ‘x’. The saturation magnetization (Ms) and anisotropic constant (K1) values lie as Ms = ∼ 0.678 – 0.754 emu/g and K1 = ∼ 1.38× 104 – 1.53× 104 erg/cm3, respectively with magnesium (x). Presence of anion vacancies and high coercivity make the materials suitable for industrial applications.

Magnetic exchange coupled composite behavior in the doped manganite nanoparticles: A proposed phenomenological model

In this paper, we comprehensively investigate the isothermal magnetization behavior of doped perovskite manganite nanoparticles. The focus is on understanding the impact of variation of particle sizes on the soft and hard magnetic phases with respect to the changes in the coercive field and remanent magnetization, both theoretically and experimentally. The study seeks to correlate experimental findings with the proposed phenomenological model to gain deeper insights into the underlying mechanisms governing exchange coupling and anisotropy effects in the nanocrystalline composites. The proposed phenomenological model beautifully demonstrates how the values of saturation magnetization and coercive field changes with changing the particle size in the nanocrystalline La0.48Ca0.52MnO3 (LCMO48) and La0.46Ca0.54MnO3 (LCMO46) compounds. In addition, the model provide an insights into the limitations of critical radius, size and shape of the nanocrystalline particle. This investigation looks into how the size of particles affects their magnetic properties, specifically coercive field and remanent magnetization.

NiCr2−xGdxO4 ceramics’ magnetic, structural and electrical conductivity as well as their activation energy properties

The goal of this work is to synthesize and characterize nanoscale nickel chromites nanoparticles doped with Gd using the economical solution combustion method. Numerous analytical techniques, including energy formation, electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction, are used for in-depth characterization. The results show that at low values of coercivity, high values of saturation magnetization, and low values of remnant magnetization, the chromites correspond. The crystalline size of Gd-doped nickel chromites decreases. For the normal spinel structure’s tetrahedral and octahedral coordinated forms, respectively. The present research shows that agglomerated forms and irregular, spherical structures formed by SEM (Scanning Electron Microscope) form regular structures. The present investigation uses a transmission electron microscope (TEM) to illustrate the formation of regular-shaped particles. As demonstrated by Gd-doped NiCr2O4 and pure NiCr2O4, stable interstitial positions are among the typical interstitial positions of the metal oxides. Investigations of magnetic properties from the paramagnetic to the ferromagnetic phase formation. Electrical conductivity and activation energy dropped with Gd doping of nickel chromites and showed an inverse relationship with particle/crystallite sizes. Lastly, applications for NiCr2−x GdxO4 particles were examined and future research directions were also suggested.

Structural and Magnetic Properties of Nano Manganite La0.6Sr0.4MnO3 Obtained by Mechanochemical Synthesis Influenced by Preparation Conditions

Single phase La0.6Sr0.4MnO3 nanoparticles with perovskite structure ( R3̅C symmetry) were successfully prepared by ball milling (mechanochemical synthesis) for 1 and 10 h followed by annealing treatment at temperature 900 or 1100 °C. It was found that, the lattice parameters increase with the increase of milling time or annealing temperature. The increase of the annealing temperature results in the increase of crystallite size and the particle size. The obtained samples were found to be ferromagnetic at room temperature. The sample obtained by one hour of milling and 900 °C annealing showed high value of saturation magnetization (about 56 emu g−1) and small value of coercivity (about 31 Oe) at room temperature, while the other samples show reduced value of magnetization and higher value of coercivity. The obtained magnetic results are discussed in light of the core/shell model of nanoparticles. The effect of the presence of oxygen vacancies on the lattice parameters and magnetic properties of the obtained samples is also discussed.

Unveiling the structural, optical, electrical, and ferromagnetic properties of Ca2+ doped mixed spinel ferrites for switching field high-frequency device applications

In this paper, the calcium-doped nickel-zinc nano-ferrites [Ni0.5Zn0.5CaxFe2-xO4; x = 0.00, 0.10, and 0.30] were prepared using the chemical co-precipitation synthesis route and studied for switching field high-frequency device applications. The structural analysis has been completed by analyzing X-ray diffraction (XRD) patterns. The Rietveld refined XRD patterns confirmed the formation of cubic spinel structure of Ca2+ substituted nickel-zinc ferrites. The detection of metal-oxygen bonds present at A and B lattice sites has been unveiled by Fourier transform infrared (FTIR) spectroscopy. The morphological studies obtained through FESEM (Field emission scanning electron microscopy) analysis showed a reduction in the particle size from 70 nm to 53 nm when the concentration of Ca2+ ions in Ni-Zn ferrites was increased. Energy dispersive spectra (EDS) confirmed the presence of elements present in the prepared composition. The structure of a cubic spinel-shaped unit cell has been verified from three active prominent Raman modes (A1g, A2g, and T2g). Diffuse-reflectance spectroscopy (DRS) exhibits the increment in the bandgap values (from 1.55 eV to 1.63 eV) which helps fabricate highly efficient photovoltaic devices. The ferroelectric measurements yielded a rise in polarization values from 1.461 μC/cm2 to 18.228 μC/cm2 for 10 % Ca2+ ion substitution. The tangent loss values declined from 24 to 3 in Ni-Zn ferrites upon substituting Ca2+ ions. The Vibrating sample Magnetometer (VSM) technique found the increment in the saturation magnetization (Ms) values from 34.724 emu/g to 54.662 emu/g on substituting up to 30 % Ca2+ ions in Ni-Zn ferrites. These obtained results support the material in switching field distribution for high-frequency applications. The results exhibited that the prepared samples can be applicable for switching devices, filters, and microwave absorption devices. The results revealed the maximum frequency between 12 and 18 GHz which is useful for Ku band absorption.

Simultaneous therapeutic and diagnostic applications of magnetic PLGA nanoparticles loaded with doxorubicin in rabbit.

In this study, DOX (Doxorubicin) and Fe3O4 magnetic nanocrystals (SPIONs (Superparamagnetic iron oxide nanocrystals)) were encapsulated in the PLGA-PEG: poly(lactide-co-glycolide)-b-poly(ethylene glycol) nanoparticles for theranostic purposes. The final prepared formulation which is called NPs (Nanoparticles) exhibited a particle size with a mean diameter of ~ 209nm and a sufficient saturation magnetization value of 1.65 emu/g. The NPs showed faster DOX release at pH 5.5 compared to pH 7.4. Also, the cytotoxicity effect of NPs increased compared to Free-DOX alone in C6 glioma cancer cells. For in vivo investigations, the 2.2 Kg rabbits were injected with NPs formulations via a central articular anterior vein in their ears. Furthermore, the images of rabbit organs were depicted via MR (Magnetic resonance) and fluorescent imaging techniques. A negative contrast (dark signal) was observed in T2 (Relaxation Time) weighted MR images of IV (Intravenously)-injected rabbits with NPs compared to the control ones. The organ's florescent images of NPs-injected rabbits showed a high density of red color related to the accumulation of DOX in liver and kidney organs. These data showed that the NPs have no cytotoxicity effect on the heart. Also, the results of histopathological tests of different organs showed that the groups receiving NPs and Free-DOX were almost similar and no significant difference was seen, except for the cardiac tissue in which the pathological effects of NPs were significantly less than the Free-DOX. Additionally, pharmacokinetic studies were also conducted at the sera and whole bloods of IV-injected rabbits with NPs and Free-DOX. The pharmacokinetic parameters showed that NPs could enhance the DOX retention in the serum compared to the Free-DOX. Altogether, we aimed to produce a powerful delivery nanosystem for its potential in dual therapeutic and diagnostic applications which are called theranostic agents.

Optimization Photodegradation of Methylene Blue Dye using Bentonite/PDA/Fe3O4@CuO Composite by Response Surface Methodology

This study aims to synthesize bentonite/PDA/Fe3O4@CuO composites as a catalyst for the photodegradation of Methylene blue dye. Composite characterization involves X-ray Diffractometry (XRD), Scanning Electron Microscopy (SEM) with X-ray Energy Dispersion Spectrometry (EDS), UV-Vis Diffuse Reflectance Spectroscopy (UV-Vis DRS), and Vibrating Sample Magnetometer (VSM). Response Surface Methodology (RSM) employs Central Composite Design (CCD) to optimize photodegradation by varying dye concentration, irradiation time, and catalyst dose. The bentonite/PDA/Fe3O4@CuO composites exhibit a saturation magnetization value of 54.82 emu/g and a band gap of 2.1 eV. The optimization revealed that concentration and dose significantly impact the photodegradation efficiency. A quadratic model is suitable for modeling the photodegradation of Methylene blue dye using bentonite/PDA/Fe3O4@CuO composites, as determined by analysis of variance (ANOVA). The optimal conditions for achieving maximum photodegradation efficiency were identified as a dye concentration of 10 mg/L, an exposure time of 90 min, and a catalyst dose of 1.67 g/L. Under these parameters, the photodegradation process exhibited a remarkable efficiency of 100%. The Bentonite/PDA/Fe3O4@CuO composites exhibited strong stability, efficiency, and recyclability. After six photodegradation cycles, there was a 5.18% decrease in photodegradation efficiency. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Structural and magnetic properties of α-Fe2O3 with lithium ferrite prepared using co-precipitation method and annealed at different temperatures

Using Co-precipitation method, an attempt was made to prepare lithium ferrite. However, during the synthesis, formation of an additional α-Fe2O3 phase along with Li0.5Fe2.5O4 was observed. To reduce the α-Fe2O3 phase, samples were annealed at 700°C, 800°C and 900°C temperatures for 2 hours. The investigated samples were then characterized using X-Ray diffraction for phase formation and Rietveld analysis was carried out to determine the different structural parameters such as phase percentage, lattice parameter and cell volume. The Chi square values were observed to be within the limit along with goodness of fit less than 3 for all the samples annealed at different temperatures. Surface morphology was carried out using scanning electron microscope and the average grain size was found to be 1.43 µm for the sample annealed at 900°C. Magnetic properties of samples were investigated, and it was observed that all the samples exhibit low values of saturation magnetization along with coercivity. The presence of two phases such as α-Fe2O3 phase and lithium ferrite phase dilutes the exchange interaction, tuning the magnetic parameters.

Fabrication of Al/Ni core–shell pigments via galvanic displacement and their application in radar-infrared compatible stealth coatings

The Al/Ni magnetic core–shell pigments were successfully synthesized in this study using the galvanic displacement method. A dense nickel shell was formed on the surface of a flake Al pigment (Al:Ni2+ = 1:0.5), resulting in a decrease in its lightness by 9 units while only slightly increasing the average infrared emissivity by 0.1 compared with the uncoated flake Al pigments. And it also exhibited soft magnetic characteristics, with a saturated magnetization value of 4.5 emu/g. Moreover, the impact of Al/Ni core-shell pigments on the infrared-radar stealth performance of the target was investigated based on the structure of “low-emissivity coating (LEC) + radar absorbing coating (RAC)”. The results showed that the emissivity of Al/Ni composite coatings maintained a low infrared emissivity (ε ≤ 0.23). The introduction of Ni shell improved the impedance matching between the Al/Ni coating and free space, allowing greater penetration of microwaves into the LEC and improving radar stealth performance of materials. The Al/Ni composite coatings (Al:Ni2+ = 1:0.5, the thickness of RAC:1.2 mm, and LEC: 60 μm) exhibited an extended effective absorption bandwidth (Reflection loss (RL) ≤ −10 dB) from 2.6 to 4.25 GHz and an enhancement of the average RL from −6.43 to −7.1 dB in the range of 2–18 GHz compared to the RAC. Consequently, the Al/Ni magnetic core–shell pigments can be used as novel low-emissivity pigments for infrared-radar compatible stealth research.

Enhancing fluoride ion removal from aqueous solutions and glass manufacturing wastewater using modified orange peel biochar magnetic composite with MIL-53

In this study, we developed new adsorbents derived from orange peel biochar (BCOP) and enhanced them with CoFe2O4 magnetic nanoparticles (BCOP/CoFe2O4) and MIL-53(Al) (BCOP/CoFe2O4/MIL-53(Al)). These adsorbents were utilized to remove fluoride (FL) ions from aqueous solutions. We analyzed the properties of these adsorbents using a range of techniques, including FTIR, XRD, SEM, EDX-Map, VSM, Raman spectroscopy, and BET. Our findings indicate that the components interact effectively with one another. Specifically, the BCOP/CoFe2O4/MIL-53(Al) sample exhibited a specific surface area of 196.430 m2/g and a magnetic saturation value of 9.704 emu/g. The maximum FL ion adsorption capacities for BCOP, BCOP/CoFe2O4, and BCOP/CoFe2O4/MIL-53(Al) were 7.618, 16.330, and 37.320 mg/g, respectively, indicating that the modifications significantly enhanced the adsorption capacity. The optimum fluoride ion removal rates using BCOP, BCOP/CoFe2O4, and BCOP/CoFe2O4/MIL-53(Al) were 97.88%, 98.23%, and 99.06%, respectively, at adsorbent doses of 2.5, 1.5, and 0.8 g/L, contact times of 90, 70, and 50 min, pH 4, temperature 50 °C, and a FL concentration of 10 mg/L. Thermodynamic studies revealed that the adsorption process was spontaneous and endothermic, with increased randomness between the adsorbent and fluoride ions. Kinetic analyses showed that fluoride ion adsorption by BCOP/CoFe2O4/MIL-53(Al) followed a pseudo-second-order (PSO) model, while BCOP and BCOP/CoFe2O4 followed a pseudo-first-order (PFO) model. Additionally, the equilibrium data for fluoride ion adsorption on BCOP/CoFe2O4/MIL-53(Al) adhered to the Freundlich model, whereas the other samples conformed to the Langmuir model. The study evaluates the effectiveness of BCOP, BCOP/CoFe2O4, and BCOP/CoFe2O4/MIL-53(Al) in removing FL ions from glass manufacturing wastewater, highlighting the superior performance of the magnetic composite due to its enhanced surface area and functional groups. Notably, the adsorbents demonstrated good regenerative capabilities, maintaining high performance over multiple adsorption cycles.

The Structural, Magnetic, and Electrochemical Properties of Composite PAni/Co<sub>0.2</sub>Mn<sub>0.8</sub>Fe<sub>2</sub>O<sub>4</sub>

The current work concerns preparing cobalt manganese ferrite (Co0.2Mn0.8Fe2O4) and decorating it with polyaniline (PAni) for supercapacitor applications. The X-ray diffraction findings (XRD) manifested a broad peak of PAni and a cubic structure of cobalt manganese ferrite with crystal sizes between 21 nm. The pictures were taken with a field emission scanning electron microscope (FE-SEM), which evidenced that the PAni has nanofibers (NFs) structures, grain size 33 – 55 nm, according to the method of preparation, where the hydrothermal method was used. The magnetic measurements (VSM) that were conducted at room temperature showed that the samples had definite magnetic properties. Additionally, it was noted that the saturation magnetization value of PAni/Co0.2Mn0.8Fe2O4 nanocomposite and Co0.2Mn0.8Fe2O4 nanoparticles are maximum saturation magnetization values of (4.7) and (9) emu g−1 respectively. Studying properties of electrochemical which were tested in 1 M of H2SO4 by using the CV cyclic voltammetry analysis, galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS), found the highest capacitance is 596 F/g.

Magnetic properties of hard-soft MnBi/FeNi@C exchange coupled nanostructures via cryo-milling

The extremely important permanent magnets encounter uncertainty and cost variations due to utilization of rare earths as prime components. Hence, the exchange coupled magnets comprised of hard and soft magnets in different proportions are explored to optimize the magnetic properties and cost. In this line, we prepared exchange coupled magnets of MnBi with FeNi@C nanoparticles (varying compositions = 10, 15 and 20 wt %) via cryogenic ball milling route. Out of these, the nanocomposite with MnBi and 15 wt% FeNi@C provided a coercivity value of 7.9 kOe with saturation magnetization and remanance values of 63 and 38 emu/g respectively. This exchange coupled magnet shown improvement in the MS, HC and Mr values by 53, 18 and 90 % respectively as compared to MnBi alone. The carbon layer over FeNi@C phase (MS = 147 emu/g) as well as cryomilling facilitated the formation of its exchange coupled magnet with MnBi.

Influence of synthesis methods on the structural, dielectric and magnetic properties of cobalt ferrites

A systematic study comprising structural, magnetic and dielectric properties of the cobalt ferrite (CoFe2O4) powders at first is carried out by way of synthesizing the materials using different preparatory methods, such as conventional solid-state method, wet chemical sol-gel autocombustion method using citric acid as well as glycine, separately as fuels. X-ray diffraction (XRD) studies reveal the formation of spinel phase with clear variations of peak intensities in all the samples. Morphology studies using scanning electron microscopy (SEM) reveal well grown grains in solid state synthesized sample compared to sol-gel autocombustion samples. The variations observed in the grain growth as well as densities (porosity) were attributed to typical temperature treatment conducted on the samples. Dielectric tests provide the evidence of space charge polarization in all the samples. Magnetic studies using vibrating sample magnetometry (VSM) provide the values of saturation magnetization and coercivity of the samples explored. The sol-gel autocombustion sample using glycine matrix (Cogly) shows higher saturation magnetization (Ms = 59.2 emu/gm) comparing to other samples whereas, sample with citric acid matrix results with lower Ms value as 36.5 emu/gm. The typical reasons for the observed variations in structural, microstructural, magnetic, dielectric and impedance properties of these materials were well addressed in terms of theoretical aspects and presented in this paper.

An assessment of the mechanically alloyed equiatomic FeCoNiMnSi high entropy amorphous alloy for non-isothermal crystallization kinetics and magnetocaloric refrigeration application

We studied an equiatomic FeCoNiMnSi high entropy amorphous alloy successfully processed via mechanical alloying technique. The structural, magnetic, and magnetocaloric characteristics of the resulting materials were examined using X-ray diffraction, field emission scanning electron microscopy, high-resolution transmission electron microscopy, and a vibrating sample magnetometer. The structural analysis showed a prominent amorphous phase formation as the milling time increases from t = 0–35h of mechanical alloying. The differential scanning calorimetry was employed to investigate the non-isothermal crystallization kinetics of the 35-h milled sample. The results revealed that the milled powder consists of a single exothermic peak with its apparent activation energy (Eg, Ex, Ep) being determined using the Kissinger, Ozawa, and Augis-Bennett equations. The findings exhibit Ex > Ep > Eg, representing that nucleation is more complicated than the growth mechanism during the crystallization process. Meanwhile, under non-isothermal conditions, the Kissinger-Akahira-Sunose, Friedman, and Flynn-Wall-Ozawa models were calculated using the local activation energies that agree with the apparent activation energy. Furthermore, the Johson-Mehl-Avrami-Kolmogorov exponent (n) and Avrami-Ozawa combined [F(T)] models exhibit high-dimensional nucleation and growth with an increasing nucleation rate enabled by lowering the local activation energies as a function of degree of conversion with respect to temperature. In magnetic measurements, a feasible mathematical model was proposed as a novel strategy for predicting the value of saturation magnetization as a milling time function. The model has an exceptional predictive capability, confirmed by fitting other research outcomes. Finally, the proposed system also delivers the best magnetocaloric properties with a maximum magnetic entropy change of 3.70 Jkg−1 K−1 at 150 K curie temperature and a refrigeration capacity of 252.86 J/kg with 1000 Oe applied magnetic field.