Saturation Magnetization Value Research Articles

Determination of organochlorine pesticide residues in food by polystyrene coated silica magnetic microspheres combined with gas chromatography-mass spectrometry

In this work, a sample pre-treatment technology, based on magnetite-silica-polystyrene (Fe3O4@SiO2@PS) composite as the adsorbent, combined with Gas Chromatography-Mass Spectrometry (GC–MS) has been developed and used for the trace analysis of organochlorine pesticide residues in food. SEM, TEM, FI-IR, VSM, XPS, BET, TGA and XRD techniques were used to characterize the synthetic adsorbent material, the adsorbent had excellent magnetic separation properties (saturation magnetization values with 32.7 emu g−1) and adsorption properties (adsorption capacity with 16.67 mg g−1 to 20.53 mg g−1), and the adsorption performance of Fe3O4@SiO2@PS aligned with the pseudo-second-order kinetics. Under the optimal conditions, the developed method showed satisfactory performance within a range of 0.01 to 4 mg L−1 (R2 ≥ 0.9971), the low detection limits (LOD) were from 0.05 to 0.20 μg kg−1, and the quantification limits (LOQ) were from 0.16 to 0.67 μg kg−1, respectively. The spiked recovery rates ranged from 74.7 % and 93.7 %, with relative standard deviations (RSD) from 2.09 % to 6.43 %. Thus, the developed adsorbent and method offer an efficient alternative to the commonly used SPE-based approach.

Synthesis and Characterization of InGaZnO Nanocomposites: An Insight of Optical, Dielectric, and Magnetic Properties

In this study, pure Indium oxide (In2O3 100%) and its composite films Indium gallium oxide (IGO 50%:50%), and Indium gallium zinc oxide (IGZO 33%:33%:34%) are deposited on glass substrate by Sol-gel dip coating method. Indium oxide and its composites have a high degree of crystallization, as evident by the strong diffraction peaks. The SEM images depict distinctly diverse morphologies of nanostructures varied in size from 22.2nm to 138nm. The wider band gap (Eg) engineering (reported (Eg≈ 3.62eV)–In2O3, (Eg ≈ 3.83eV)–IGO, (Eg≈3.74eV) –IGZO) and heterostructure formation is also advantageous for novel In2O3 applications in advanced (transparent) devices and sensors. Complex impedance analysis provides insights into the grains and grain boundaries of In2O3 and its composite films (IGO, IGZO). The VSM measurements confirms that IGZO has a higher saturation magnetization value of 13.33emu/cm3 and a lower coercivity value of 429.54Oe as compared to In2O3 and IGO highlighting their magnetic properties suitable for spintronic and high-frequency device applications.

Design of superparamagnetic Fe3O4@SiO2@3,4-DABP nanocatalysts, fabrication by co-precipitation and sol-gel methods, characterization of detailed surface texture properties and investigation of solar cell performance

This research focuses on the synthesis, characterization, and evaluation of Fe3O4, Fe3O4@SiO2, and Fe3O4@SiO2@3,4-DABP magnetic nanocatalysts (MNCs) for their potential use as sensors within the intricate architectures of solar cell devices. Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and Brunauer-Emmett-Teller (BET) surface area measurements were carried out to characterize the structural, morphological and magnetic properties of the MNCs. The MNCs exhibit an average particle size of approximately 10 nm. Fe3O4, Fe3O4@SiO2, and Fe3O4@SiO2@3,4-DABP MNCs have saturation magnetization values ​​of 61.64 emu/g, 37.31 emu/g, and 20.13 emu/g, respectively. Thermal analysis reveals mass change losses of 6.5%, 12% and 28.1%, respectively, indicating different thermal stability profiles. It confirms that their crystal structure is face-centered cubic spinel, with type IV hysteresis loops and H3 loops indicating a mesoporous structure according to the IUPAC classification. Efficiency tests of Fe3O4, Fe3O4@SiO2 and Fe3O4@SiO2@3,4-DABP MNCs in solar cell devices show efficiencies of 1.49%, 1.77% and 2.15%, respectively. As the hierarchical modification of the MNCs increases, the efficiency of the solar cell devices increases. These results highlight the potential of Fe3O4, Fe3O4@SiO2 and Fe3O4@SiO2@3,4-DABP as promising sensitizers in solar cell technology. Fe3O4@SiO2@3,4-DABP MNCs have high catalytic activity, chemical stability, electronic conductivity and low cost. This study also marks the first demonstration of the effectiveness of environmentally friendly Fe3O4@SiO2@3,4-DABP MNCs in enhancing solar cell performance, prepared via a cost-effective, simple and eco-friendly approach.

Enhancement of the magnetocaloric effect in Nd0.6-xGdxSr0.4MnO3 (0.02 ≤ x ≤ 0.1) perovskite manganites: the role of Gd3+ ionic substitution

The influence of Gd3+ doping on the magnetocaloric properties of Nd0.6-xGdxSr0.4MnO3 (0.02 ≤ x ≤ 0.1) compounds, prepared using auto-combustion sol-gel technique, has been studied . Rietveld refinement of the X-ray diffraction (XRD) data has shown all compounds to be nanocrystalline with single-phased orthorhombic structures that index to the Pnma space group. The unit cell volumes reduce as the Gd3+ ions gradually substitute the Nd3+ones. The tuning Mn4+/Mn3+ ratio for all compounds, which are slightly lower than that of the Gd-free compound, demonstrates almost equal amounts of both ions. A ferromagnetic-to-paramagnetic transition is observed with rising temperature wherein the Curie temperature (TC) gradually drops with increasing Gd3+ concentration (x). All materials exhibit ferromagnetism at 2 K, with saturation magnetization values that increase slightly with x. Both the calculated maximum magnetic entropies () and relative cooling powers (RCP) increase to relatively large values with increasing temperature and x values. The values obtained for and RCP for Nd0.6-xGdxSr0.4MnO3 (0.02 ≤ x ≤ 0.1) are comparable with those of standard pure Gd revealing their potential as magnetic refrigeration systems.

Development of the magnetodielectric properties of BaTiO3-CoFe2O4 multiferroic composites

The lead-free x CoFe2O4 – (1-x) BaTiO3 (x= 0, 0.075, 0.15, 0.225, and 1) composites have been prepared via the solid-state process. The composites' microstructure, dielectric, ferroelectric, ferromagnetic, and magnetodielectric (MD) properties were investigated. Notably, XRD analysis indicates a decrease in the tetragonality factor (cT/aT) of the BTO phase, accompanied by an expansion of the unit cell as x increases from 7.5 to 22.5 wt.%. According to the FESEM images, the CoFe2O4 (CFO) grains are uniformly distributed in the matrix with the formation of no impurity phase. The optimal dielectric properties (dielectric constant (εr) ∼ 2018 and dielectric loss factor (tan δ) ∼ 0.16) and ferroelectric characteristics (saturation polarization (PS) ∼ 12 μC/cm2 and remnant polarization (Pr) ∼ 10 μC/cm2) are achieved at x=7.5 wt.%, attributed to the minimal presence of the non-ferroelectric CFO phase. By increasing the ferrite content (up to 22.5 wt.%), the ferroelectric properties of the samples showed a gradual diminution. Also, from x=7.5 to 22.5 wt.%, a sharp increase in the saturation magnetization (from 3.75 to 11.3 emu/g) and remnant magnetization (from 0.93 to 2.35 emu/g) values was observed, while the coercivity diminished from 475.8 to ∼ 272 Oe. The simultaneous observation of two ferroic characteristic hysteresis loops validated the multiferroicity of the composites (x=7.5, 15, and 22.5 wt.%). The maximum MD constant (4.68%) was measured for x=22.5 wt.% composite at the applied magnetic field of 7 kOe.

Influence of oxygen impurities in generating ferromagnetism in GaN doped with Mn, Fe, and Cr

We report the influence of oxygen impurities in generating ferromagnetism in GaN doped with Mn, Fe, and Cr through superexchange involving Mn–O–Mn, Fe–O–Fe, and Cr–N–Cr atomic configurations. Density Functional Theory (DFT) calculations demonstrated that these configurations originate within VGa-ON\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${V}_{\ ext{Ga}}-{O}_{\ ext{N}}$$\\end{document} complex defects by incorporating Mn2+, Fe2+, and Cr3+ ions into gallium vacancies (VGa\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${V}_{\ ext{Ga}}$$\\end{document}) sites promoted by the presence of oxygen as a substitutional impurity (ON\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${O}_{\ ext{N}}$$\\end{document}). These co-doped GaN microstructures were synthesized using the thermal evaporation method. Cathodoluminescence (CL) and photoluminescence (PL) measurements confirmed the presence of VGa-ON\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${V}_{\ ext{Ga}}-{O}_{\ ext{N}}$$\\end{document} complex defects in all GaN-grown samples. X-ray photoelectron spectroscopy (XPS) measurements confirmed the successful incorporation of Mn2+, Fe2+, and Cr3+ ions in GaN samples. SQUID measurements demonstrated room-temperature ferromagnetism with respective saturation magnetization (Ms) and coercive field (Hc) values of ± 1.5 × 10−5 emu and 4 mT for GaN:O,Mn, ± 4.4 × 10−5 emu and 2.6 mT for GaN:O,Fe, and ± 1.7 × 10−5 emu and 2.6 mT for GaN:O,Cr.

Nanostructured spinel ferrites: A comprehensive study on the synthesis, characterization, and magnetic properties of Zn and Mn substituted magnetite nanoparticles produced through the co-precipitation method

Seven cubic spinel ferrite nanoparticles were successfully synthesized through the co-precipitation method. These nanoparticles include Fe3O4, Zn0.4Fe0.62+Fe23+O4, Mn0.4Fe0.62+Fe23+O4, Zn0.6Mn0.4Fe0.42+Fe1.63+O4, Zn0.4Mn0.6Fe0.42+Fe1.63+O4, Zn0.4Mn0.4Fe0.22+Fe23+O4, and Zn0.4Mn0.4Fe0.42+Fe1.83+O4. The Rietveld method was used to analyze X-ray diffraction data, confirming that all samples have a single-phase cubic spinel structure. The presence of zinc and manganese ions in magnetite lattice leads to changes in lattice parameters and crystallite size, resulting in a range of 7–12 nm crystallite sizes. Fourier transform infrared spectroscopy (FT-IR) analysis of nanoparticles reveals two significant adsorption peaks at 560-576 cm−1 and 437-449 cm−1, corresponding to metal ion stretching vibrations at tetrahedral and octahedral sites. The X-ray photoelectron spectroscopy (XPS) analysis revealed the presence of iron, zinc, and manganese in various oxidation states. Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) images showed spherical, agglomerated nanoparticles. The study confirmed the elemental composition and mapping images of prepared samples using energy-dispersive X-ray spectroscopy (EDS). The magnetic properties of the synthesized nanoparticles were meticulously examined utilizing a vibrating sample magnetometer (VSM) at room temperature. A direct correlation is established between the structural alterations induced by Zn2+/Mn2+ and their subsequent effects on magnetic characteristics, specifically through the reallocation of cations and the mechanisms of electron hopping occurring at the B-sites. The structural modifications result in enhanced superparamagnetic behavior, exhibiting saturation magnetization values between 46.01 and 69.38 emu/g. The sustainable characteristics of these materials render them highly viable options for applications in environmental remediation and green technology.

Significant enhancement in the magnetic properties of Cr2Te3 nanosheets by atom substitution doping.

Ferromagnetic Cr2Te3 nanocrystals, with their high spin-orbit coupling and low symmetry, have attracted considerable attention as rare-earth-free magnetic nanomaterials due to their potential to achieve high magnetic anisotropy. However, their relatively low values of remanence (Mr) and saturation (MS) magnetisation limit their energy product, making them unsuitable for practical applications. Herein, we report a straightforward one-pot heat-injection technique for the synthesis of high-remanence hexagonal Cr2Te3 nanosheets by heterogeneous doping with atoms of M (M = V, Mn and Se). The doped materials provide enhanced Mr and MS at an unchanged Curie temperature (TC), resulting in excellent hard magnetic properties. With Mn doping, the Mr of the matrix increases significantly, reaching 18.38 emu g-1 at 5 K, far exceeding the original undoped Cr2Te3 nanosheets. The nearly square hysteresis loop makes it valuable for many low temperature applications. These results provide a valuable case for tuning the magnetism of ferromagnetic Cr2Te3 by substitutional doping.

Tuning the physical properties of ternary alloys (NiCuCo) for in vitro magnetic hyperthermia: experimental and theoretical investigation

Most of published research on magnetic hyperthermia focused on iron oxides, ferrites, and binary alloy nanostructures, while the ternary alloys attracted much limited interest. Herein, we prepared NiCuCo ternary alloy nanocomposites with variable compositions by mechanical alloying. Physical properties were fully characterized by XRD, Rietveld analysis, XPS, SEM/EDX, TEM, ZFC/FC and H-M loops. DFT calculations were used to confirm the experimental results in terms of structure and magnetism. The results showed that the fabricated nanoalloys are face centered cubic (FCC) with average core sizes of 9–40 nm and behave as superparamagnetic with saturation in the range 4.67–42.63 emu/g. Langevin fitting corroborated the superparamagnetic behavior, while law of approach to saturation (LAS) was used to calculate the magnetic anisotropy constants. Heating effciencies were performed under an alternating magnetic field (AMF, H0 = 170 Oe and f = 332.5 kHz), and specific absorption rate (SAR) values were determined. The highest magnetic saturation (Ms), heating potentials, and SAR values were attained for Ni35Cu30Co35 containing the lowest Cu but highest Ni and Co percentages, and the least for Ni15Cu70Co15. Importantly, the nanoalloys reached the required temperatures for magnetic hyperthermia (42 °C) in relatively short times. We also showed that heat dissipiation can be simply tuned by changing many parameters such as concentration, field amplitude, and frequency. Finally, cytotoxicity viability assays against two different breast cancer cell lines treated with Ni25Cu50Co25 nanoalloy in the presence and absence of AMF were investigated. No significant decrease in cancer cell viability was observed in the absence of AMF. When tested against tumorigenic KAIMRC2 breast cancer cells under AMF, the NiCuCo nanoalloy was found to be highly potent to the cells (~ 2-fold enhancement), killing almost all the cells in short times (20 min) and clinically-safe AC magnetic fields. These findings strongly suggest that the as-prepared ternary NiCuCo nanoalloys hold great promise for potential magnetically-triggered cancer hyperthermia.

Magnetic and visible light-induced novel green synthesized magnetic Co3O4 photocatalysts via sunflower seed meal extract for anionic and cationic dye removal by adsorption assisted photocatalytic degradation

This study was aimed at the preparation of m-Co3O4 NPs (magnetic Co3O4 nanoparticles) from sunflower seed meal (SFSM) which is the waste of sunflower seed oil factories, and their application as a photocatalyst for the adsorption assistant photocatalysis degradation of methylene blue (MB), and direct yellow-50 (DY-50) under the visible irradiations. Also, the photocatalytic performance of m-Co3O4 NPs was evaluated in synthetic wastewater. The produced m-Co3O4 NPs were ferromagnetic with a saturation magnetization value of 4.3 emu g−1 and the degradation of cationic MB and anionic DY-50 dyes by 100% and 93% in 20 min and 35 min, respectively, by adsorption-assisted photocatalytic process under visible light was achieved. The reactions were found to be pseudo-second-order equation for the adsorption-assisted photocatalytic process for both dyes. The photocatalytic activity of m-Co3O4 NPs decreased slightly even after five repeated cycles. These results show that the m-Co3O4 NPs can be used successfully in dye treatment in wastewater with their adsorption-assisted photocatalytic properties, activation by visible light, magnetic separability, and low-cost production.

A study on BaTiO3 – NiFe2O4 composite; microstructure, multiferroic and magnetodielectric properties

The lead-free x NiFe2O4 – (1-x) BaTiO3 (x = 0, 0.05, 0.1, 0.15) multiferroic composites were prepared via the solid-state sintering technique. Microstructure, multiferroic, and magnetodielectric properties of composites were investigated. According to the XRD data (from x = 5 to 15 wt%), the tetragonality factor (cT/aT) and unit cell volume of the BaTiO3 (BTO) crystal system diminished. Based on SEM images, ferromagnetic NiFe2O4 (NFO) grains are uniformly dispersed in the ferroelectric BTO matrix without additional reaction in the interfaces of two phases. The highest values of dielectric (dielectric constant (εr) ∼ 1905 and dielectric loss factor (tan δ) ∼ 0.049) and ferroelectric properties (saturation polarization (PS) ∼ 13 μC/cm2 and remnant polarization (Pr) ∼ 10 μC/cm2) are attained for x = 5 wt% due to the lowest NFO (non-ferroelectric) concentration. Also, with increasing ferrite concentration (up to 15 wt%), the ferroelectric properties of the composites show a gradual decrease. The saturation magnetization (MS) values rise due to increasing ferrite concentration (from 2 to 5 emu/g for x = 5 to 15 wt%). Moreover, coercivity (HC) drops from 150 to 110 Oe. The simultaneous observation of the ferroelectric and ferromagnetic characteristic hysteresis loops confirmed the multiferroic effect for x = 5, 10, and 15 wt%. The highest magnetodielectric constant (3 %) is obtained for x = 15 wt% multiferroic composite at the applied magnetic field of 6 kOe.

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 6.36 emu/g, respectively. The maximum dye removal using PC/Cloisite 30B/ZnFe2O4 (99.08 %) was determined at pH=10, adsorbent dose of 1 g/L, time of 50 min, temperature of 25 °C, and MB concentration 10 mg/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 43.47 mg/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.

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.

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.

Hybrid CoFe2O4-CNTs-graphene: Synthesis and characterization for energy storage devices

Hybrid materials play a crucial role in a spectrum of energy storage devices. Among them CoFe2O4–CNT–graphene hybrid stands out as versatile magnetic materials with wide-ranging applications spanning electronics, magnetism, and sensor industries. In this study, we synthesized CoFe2O4–CNT–graphene hybrid utilizing ultrasonication method. This fabrication method resulted in the formation of CoFe2O4 nanoparticles, along with bamboo-like carbon nanotubes (CNTs) and graphene nanosheets which collectively establish an open three-dimensional structure. Thorough analyses were conducted on the synthesized nano-composites employing various characterization techniques such as XRD, FT-IR, Raman and FESEM. Further characterization through XPS confirmed the formation of spinel ferrites, detecting the presence of carbon sp2, C1s, carboxylates (O-C-OH), and sp3 carbon, indicating the presence of carbon‑carbon (CC) bonds and confirms the energy levels of Co2p1/2 and Co2p3/2 indicating the effective incorporation of CFO onto the CNT/graphene surface. Analysis of dielectric parameters revealed promising characteristics for high-frequency devices, attributed to low dielectric loss, high quality factor, short relaxation time, and diverse responses exhibited by these materials. The M–H loops of the composite samples displayed ferromagnetic hysteresis behavior due to the presence of ferrite in the matrices. The coercivity value shows a slight improvement in the hybrid samples, while saturation magnetization values decrease, indicating a 1:1 weight ratio of ferrite particles to the host matrix with the incorporation of nonmagnetic CNTs and graphene, and the Hc value increases with the addition of these carbon-based materials due to increased surface anisotropy energy. Upon evaluation of dielectric and magnetic properties the hybrid materials demonstrated an enhanced dielectric and magnetic properties which render these materials suitable for utilization across a spectrum of energy storage devices.

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.

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.