Vibrating Sample Magnetometer Research Articles

Microstructural, dielectric, electrical, electromagnetic, and magnetic property enhancements in GdIG /TrIG/ Mn0.2Co0.3Zn0.5Fe2O4 ferrites composites for electronic devices application

Gadolinium garnet ferrite (GdIG) and terbium garnet ferrite (TrIG), known for their favourable magnetic and dielectric characteristics, were combined with doped zinc spinel ferrite (GdIG)x-(TrIG)y/Mn0.2Co0.3Zn0.5Fe2O4(1-x-y) (at x=1 y=0, x=0 y=1, x=y=0.5, x=y=0.25, x=y=0) to achieve improved permittivity, permeability and magnetic properties with reduced magneto-dielectric losses. Our study details the synthesis process and the resulting enhancements in structural, magnetic, and dielectric properties of the prepared samples. Analysis of the X-ray diffraction (XRD) patterns confirmed the presence of a crystalline structure characterized by both cubic spinel and cubic garnet phases in the composites. The microstructures of the composites were analysed with field emission scanning electron microscopy (FESEM), revealing the variation in a grain size from 0.11 μm to 0.96 μm at x =y=0.5. A thorough link between the crystal structure and XRD spectra, transmission electron microscope (TEM), and selected area electron diffraction (SAED) patterns have all been investigated in order to enhance the characterisation of the samples. At 1KHz, the composites exhibit highest electrical resistivity values of 5.9×106 Ωm and 2.6×106 Ωm. With the incorporation of spinel ferrites in garnet ferrite composite (x=y=0.25) the highest value of dielectric constant (885.2) and low value of dielectric loss (0.07) at 100 KHz has been obtained. Permeability values, derived from permittivity data, showed an increase in real permeability values of from 1.4×1012 to 9.2×1017 for x=y=0.5 to x=y=0.25 composite. Vibrating sample magnetometer (VSM) further confirm that the composite x=y=0.25 has highest magnetic saturation (148.8 emu/g), coercivity (502 Oe) and microwave operating frequency (33.6 GHz). The observed high dielectric constant, low loss values, switching field distribution and good magnetic properties suggest the potential suitability of these samples for various electronic devices like: high frequency devices, antennas, switching devices and magnetic recording devices.

Synthesis of Trimanganese Tetraoxide (Mn3O4) as a promising electrode and Photocatalyst for the degradation of Rhodamine B dye

The article involves the facile bio-synthesis of Manganese (III) Oxide (Mn3O4) nanoparticles (NPs) using Curry leaf (Murraya Koenigii) extract as an efficacious chelating agent. The prepared NPs were subjected to various characterization methods such as Powder X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) with Energy Dispersive X-Ray (EDX) Analysis, Transmission Electron Microscopy (TEM), Fourier Transform Infrared analysis (FTIR), Ultra Violet spectroscopy study (UV–Vis), Cyclic Voltammetry (CV) and Vibrating Sample Magnetometer (VSM) to study the crystalline structure, morphology, optical properties, electrochemical activity and magnetic property of the sample. The XRD result proved the crystallinity of the sample having crystallite size around 15 nm with tetragonal structure. The absorption band observed at 612 cm−1 indicates the Mn-O stretching modes of tetrahedral sites in FTIR analysis of the prepared sample which confirmed the formation of Mn3O4 NPs. Using SEM and TEM techniques, the surface morphology and NPs size were examined. The composition and distribution of the NPs was verified using EDX spectrum and elemental mapping. Using the UV–Visible spectroscopy, the energy band gap (Eg) for the NPs was computed and calculated as 2.34 eV. The Mn3O4 NPs evinced a specific capacitance of 276 Fg-1 at 10 mV/s scan rate. This result proposes that the obtained Mn3O4 NPs can be used as a suitable electrode mainly for supercapacitor applications. VSM study revealed the paramagnetic behavior of the synthesized Mn3O4 NPs. The synthesized Mn3O4 NPs exhibited moderate antibacterial activity with gram positive bacteria such as Staphylococcus aureus, Streptococcus pneumoniae, and gram negative bacteria such as Klebsiella pneumoniae, with the inhibition zones of 12, 10, and 9 mm respectively. Photo catalytic degradation study was carried out for Rhodamine B (RhB) dye, which showed a strong characteristic absorption peak nearly at 554 nm with 94 % of degradation efficiency.

Preparation of an imidazolium-based poly(ionic liquid) functionalized magnetic three-dimensional graphene oxide for magnetic solid phase extraction of pyrethroids from tea samples

In this work, an imidazolium-based poly(ionic liquid) (poly(1-dodecyl-3-vinyl-imidazolium bromide) functionalized magnetic three-dimensional graphene oxide (Fe3O4@3D-GO@poly(ImC12+Br−)) was synthesized via a vacuum freezing-drying method and used as a magnetic solid phase extraction (MSPE) adsorbent for the efficient extraction of pyrethroid pesticides from tea samples. The prepared Fe3O4@3D-GO@poly(ImC12+Br−) was confirmed by scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FT-IR), vibrating sample magnetometer (VSM) and X-ray photoelectron spectrogram (XPS). Due to its large specific surface area and the ability to offer multiple intermolecular interactions, including π-π stacking, hydrophobic and hydrogen bond interactions, the prepared Fe3O4@3D-GO@poly(ImC12+Br−) showed high extraction efficiency for pyrethroids. The experimental parameters were optimized by a combination of single-factor method and Box-Behnken design to improve the extraction efficiency. Under the optimum conditions, coupled with high performance liquid chromatography (HPLC), a sensitive analytical method was developed for the determination of pyrethroids, and the proposed method showed wide linear ranges (1.00–100 μg L−1) with correlation coefficients (R) ranging from 0.9980 to 0.9994, low limits of detection (0.100 μg L−1) and good repeatability with intra-day relative standard deviations (RSDs) in the range of 2.90–5.53 % and inter-day RSDs in the range of 1.83–7.76 %. Moreover, the developed method was successfully applied to the determination of pyrethroids in tea samples and satisfactory recoveries ranging from 82.37 % to 114.34 % were obtained. The results showed that the developed Fe3O4@3D-GO@poly(ImC12+Br−) was an ideal, effective and selective material for the extraction and enrichment of pyrethroids from tea samples.

Investigating the synergistic effect of Nd3+ and Ni2+ in CuO nanocrystals on their structural, optical, and magnetic properties for photovoltaic and photocatalytic implementations

The wet chemical precipitation technique was used to synthesize CuO, Nd:CuO and Ni-Nd:CuO nanoparticles efficiently. The produced substance was tested using X-ray diffraction (XRD) for confirming the crystallite structure, and scanning electron microscopy (SEM) was used to examine the morphological properties of the produced materials. Crystal defects and optical properties of the synthesized samples were analyzed through luminescence (PL) investigations and UV–Vis spectroscopy. EIS spectrum was utilized to study the electrochemical behavior of the prepared material. Vibrating Sample Magnetometer (VSM) was employed to examine the magnetic properties influencing from the doping of Ni2+ and Nd3+ ions into CuO, attributed to their substantial magnetic moment and ferromagnetic traits. Photovoltaic efficiency of the prepared material was studied by J-V characteristics and photon-to-electron converting efficacy (IPCE) studies. Photocatalytic properties were studied by degrading MB and RhB dyes. The enhancement in the photocatalytic performance of the Ni-Nd:CuO was a result of suppression of photogenerated electron-hole pair recombination and accelerated separation and migration of photogenerated charges.

Power dependent tunable optical nonlinearity in Iron oxide/Borophene core-shell nanoparticles under ultrashort laser excitation

Two-dimensional (2D) nanomaterials find immense applications in ultrafast photonics and optical switching systems due to their fascinating nonlinear optical (NLO) characteristics. This work presents a systematic investigation of laser power-dependent nonlinear optical characteristics of borophene nanosheets in a core-shell nanostructure. For this purpose, we have synthesized Borophene encapsulated Iron oxide (Fe3O4) core-shell nanoparticles (Fe3O4/Borophene CSNPs). The CSNPs were synthesized by mixing and annealing sodium borohydride (NaBH4) as a boron precursor with iron oxide nanoparticles (Fe3O4 NPs) in a controlled environment using chemical vapor deposition technique (CVD) followed by characterization using XRD, FTIR Spectroscopy, UV–vis absorption spectroscopy, TEM, SEM, and EDX techniques. Magnetic properties were analyzed by a vibrating sample magnetometer (VSM) which shows that the saturation magnetization of Fe3O4 NPs increases after being encapsulated in borophene nanosheets. The role of borophene in modifying the NLO characteristics of Fe3O4/Borophene CSNPs was studied using a power-dependent Z-scan technique utilizing ultrashort (femtosecond) laser pulses at a wavelength of 800 nm in both open and close aperture configuration. It was found that borophene-coated Fe3O4 NPs reveal tunable NLO properties that resemble the NLO characteristics of borophene nanosheets with enhanced features. This provides insights into an interaction between materials in NLO phenomena and illustrates the distinctive performance of the core-shell nanostructure. The tunable NLO properties of Fe3O4/Borophene CSNPs offer an innovative approach for developing optoelectronics and ultrafast nonlinear photonic devices.

Magnetic recyclable chitosan-graphene immobilized microcystinase A: Removal of microcystins from harmful microcystis blooms

Harmful Microcystis blooms and microcystins have become a major hidden threat to the safety of the water environment. The application of enzymatic degradation of microcystins has been severely limited by the complex environment. In this study, chitosan-graphene (CG), prepared from green biomass, was employed as matrix material, loaded with 100–200 nm Fe3O4 nanoparticles (MCG) and immobilized microcystinase A (MlrA@MCG). The preparation of MlrA@MCG was characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, vibrating sample magnetometer and fluorescence labelling. The results of the activity analysis demonstrated that MlrA@MCG exhibited superior degradation activity for MCs, as well as enhanced heat and alkaline resistance in comparison to free MlrA. Furthermore, MlrA@MCG can be recovered simply by means of a magnetic field, and its activity remains at 48.6 % after 10 repeated uses. More importantly, MlrA@MCG and the degradation products of MC-LR were not found to be cytotoxic to human cells. It is interesting that the immobilization of MlrA resulted in a reduction in the cytotoxicity of MCG. 0.2 U of MlrA@MCG can still degrade MC-LR from 232.64 μg L−1 to 94.39 μg L−1 in water from simulated severe Microcystis blooms within 24 h, showing excellent catalytic activity and stability. The study proposed a secure and efficacious approach for the elimination of microcystins from harmful Microcystis blooms, offering a promising avenue for the improvement of environmental safety.

Influence of Nd3+ on structural, electrical and magnetic properties of Ni-Cd nanoferrites

Here in we report the nanocrystalline Ni1-xCdxNdyFe2-yO4 (0 ≤ x ≤ 1.0 in steps of 0.2: y = 0.0; 0.1) ferrites were synthesized by novel solution combustion technique. The sintered powders have been characterized by X-ray diffraction (XRD), Fourier transmission infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Energy dispersive analysis by x-rays (EDAX) methods. DC electrical conductivity carried out by two probe method. Magnetic parameters were measured using vibrating sample magnetometer with an applied magnetic field up to 15 kOe at 300K. The XRD results confirmed the formation of single phase cubic spinel structure formation. It was found that the lattice parameter increased with increase in Cd2+ ion. The crystallite sizes have been found in the range of 44.24 nm–15.467 nm. Moreover, the formation of two prominent absorption bands confirmed the spinel structure. The SEM micrographs evidenced almost spherical shaped, agglomerated and grainy structure of nanoferrites. Moreover, the Curie temperature (TC) was decreased with increasing temperature and exhibit the semiconducting behaviour. Further, saturation magnetization (MS), remanence magnetization (Mr); coercivity (HC) were decrease with increase in the magnetic field. The magnetic parameters; MS, Mr, nB increases attain maximum thereafter decreases with increase in Cd2+ ion and Nd3+ ion content.

Microstructure evolution and magnetic characteristics of a novel high entropy alloy produced by mechanical alloying and spark plasma sintering

In this research, CoMoMnNiV high entropy alloys were successfully prepared by mechanical alloying (MA) and spark plasma sintering (SPS). The microstructure, phases and magnetic properties of the as-milled powders and bulk sample were examined, employing X-ray diffraction, differential scanning calorimeter (DSC), scanning electron microscopy, and Vibrating Sample Magnetometer (VSM) techniques. The resultant phase following MA exhibits a dual-phase microstructure comprising BCC and FCC solid solutions, with individual crystal dimensions below 18 nm. Thermal stability assessment via DSC reveals the alloy robustness up to 1216 °C. The SPS was performed on the MA samples at 980 °C and 50 MPa pressure, and their density was determined to be 89.64 %. The sample subjected to a milling duration of 40 h demonstrated a saturation magnetization of 25.977 electromagnetic units per gram (emu/g) and a coercivity of 371.5 Oersteds (Oe).

Carbonyl Iron Particles’ Enhanced Coating Effect Improves Magnetorheological Fluid’s Dispersion Stability

The coating effect of 1,2-bis(triethoxysilyl)ethane (BTES) on carbonyl iron particles (CIPs) was enhanced by etching with hydrochloric acid (HCl) of various concentrations, and magnetorheological fluids (MRFs) with significantly improved dispersion stability were obtained. The microstructures, coating effect, and magnetism of CIPs were examined using scanning electron microscopy (SEM), automatic surface and porosity analysis (BTE), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and a vibrating sample magnetometer (VSM), respectively. Furthermore, the rheological properties and dispersion stability of the MRFs were assessed by a rotating rheometer and a Turbiscan Tower. The results show that as the HCl concentration increased, nanopores appeared on CIPs and then disappeared, and the specific surface area of the particles increased and then decreased. When the concentration of HCl was 0.50 mol/L, the number of nanopores and the specific surface area of particles changed sharply. Not only that, the coated mass of BTES increased greatly and the saturation magnetization of particles decreased sharply. As the coated mass increased, without a magnetic field, the viscosity and shear stress of the MRFs increased, especially when the coated mass was more than 2.45 wt.%; while under a magnetic field, the viscosity and shear stress decreased, and the sedimentation rate of the MRFs decreased from 0.13 to 0.01 mm/h. By controlling the concentration of HCl for etching, the coating effect of CIPs was greatly enhanced, and thus an MRF with superior shear stress and excellent dispersion stability was obtained, which is significant in basic research and MRF-related applications.

Synthesis and characterization of AlxCu0.7Mn0.3Fe2-xO4 ferrite and its application in adsorption of dyes

The increasing presence of artificial dyes in industrial wastewater has necessitated the development of efficient and sustainable adsorption materials. This work explores the synthesis and characterization of Al-doped Cu-Mn (AlxCu0.7Mn0.3Fe2-xO4, where x = 0.1, 0.3, 0.5, 0.7, and 0.9) ferrite as a new adsorbent for the removal of dyes from aqueous solutions. The Al-doped Cu-Mn ferrite was prepared using the solution combustion method and meticulously characterized using various physiochemical techniques, including scanning electron microscopy (SEM) analysis, Fourier transform infrared spectroscopy (FTIR), X-ray powder diffractometer (XRD), vibrating sample magnetometer (VSM), and Brunauer-Emmer-Teller (BET). Adsorption studies tested the material's ability to remove hazardous dyes such as congo red, methyl orange, methylene blue, and crystal violet from aqueous solutions. The effects of various parameters, including temperature, contact time, and initial dye concentration, were systematically studied. To understand the mechanism of interaction between the adsorbent and the dyes, the adsorption isotherms were examined using the Langmuir, Temkin, D-R, and Freundlich models. The Freundlich isotherms provided the best fit for the experimental data. To clarify the kinetics of the adsorption process, kinetic experiments were conducted using pseudo-first and pseudo-second-order. According to the results of the kinetics analysis, pseudo-second-order kinetics fit the data better, with a higher coefficient of determination values (R2 = 0.981, 0.983, 0.984 & 0.984). Thermodynamic parameters, including enthalpy, Gibbs free energy, and entropy changes, were calculated to determine the nature of the adsorption process, and the result demonstrates that the adsorption process was endothermic and naturally spontaneous. The results indicate that Al-doped Cu-Mn ferrite exhibits high adsorption capacities and favourable thermodynamic properties, making it a promising material for the removal of dyes from industrial wastewater effluents. The study contributes to the field by providing insights into the adsorption mechanisms and potential applications of Al-doped Cu-Mn ferrite in environmental remediation.

Investigate Performance of ATGF nanocomposite based on guar gum polymer for adsorption of Congo Red dye and alpha lipoic acid drug from wastewater: study kinetics and simulation

AbstractIn this study, the synthesized nanocomposite novel arginine/thiourea/guar gum/ferrite (ATGF) adsorbent was evaluated for the adsorption of alpha lipoic acid (ALA) and Congo Red (CR) from wastewater. The synthesized nanocomposite was examined by Brunauer–Emmett–Teller theory (BET), Termal gravimetric analysis (TGA), Fourier transform infrared spectrometer (FT‐IR), field emission scanning electron microscopy (FE‐SEM), X‐ray Diffraction (XRD), Vibrating sample magnetometer (VSM), and energy dispersive X‐ray (EDX). For the removal of ALA and CR from aqueous solution, the capacity of the nanocomposite was investigated by working on a series of experiments such as the effect of adsorbent dose, initial concentration, contact time, pH and temperature. The adsorption kinetics of these two pollutants were investigated using pseudo‐first‐order and pseudo‐second‐order velocity equations. The nanocomposite kinetics follow pseudo‐second‐order. Langmuir and Freundlich isotherms were investigated. The results show that the Langmuir isotherm model gives the maximum adsorption capacity of ALA as 96.93 mg g−1 and of CR as 229.34 mg g−1 on the nanocomposite. © 2024 Society of Chemical Industry.

Novel CdFe2O4 nanoparticles facile synthesis and their applications towards practical ammonia detection: an effect of annealing

Cadmium ferrite (CdFe2O4) nanoparticles were synthesized via a simple co-precipitation method, and the effect of annealing temperature over the prepared samples’ structural, morphological, and optical properties was analyzed by varying the temperatures 700, 800, and 900 °C. The x-ray diffraction (XRD) studies revealed that the prepared samples are highly crystalline in nature and belong to a cubic spinel crystal structure, and the crystallite size increases from 32 to 59 nm with respect to the increasing temperature. The surface morphology of the ferrite samples showed the uniformly distributed highly agglomerated particles with larger voids for the ferrite nanoparticles annealed at 900 °C. Optical properties of the prepared CdFe2O4 samples were carried out by diffused reflectance spectroscopy (DRS) and the optical band gap of the samples were found to be 2.57, 2.55 and 2.53 eV. The Vibrating sample magnetometer (VSM) studies at room temperature showcased that the nanoparticle samples possess ferromagnetic behavior, and the magnetization (Ms), Coercivity (Hc), and Retentivity (Mr) values were found to be 27.5 × 10−3 emu g−1, 237.60 Oe, and 1976 × 10−6 emu/g for the CdFe2O4 sample annealed at 900 °C. The gas sensing studies were carried out with the presence of target gas ammonia, and its significant sensing parameters such as gas responsivity (S%), rise time, and recovery times were determined, and these values of CdFe2O4 samples annealed at 900 °C were observed to be 1610%, 7.1 s, and 2.2 s. Our findings strongly suggest that the CdFe2O4 samples annealed at 900 °C hold significant promise as a multifunctional material, particularly in gas-sensing applications. This potential opens an exciting avenue for further research and development.

Synthesis and characterization of bentonite-based NiO nanoparticles as bi-functional heterogeneous catalyst for efficient synthesis of 1,8-dioxo-decahydroacridines

A straightforward, expeditious, robust, and efficient synthesis of NiO@Bentonite nanocatalyst was done using a simple microwave method. The X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), Brunauer–Emmett–Teller (BET), thermal behavior analysis, and vibrating sample magnetometer (VSM) techniques were used to characterize the physicochemical properties of the NiO@Bentonite nanocomposites. The outcomes demonstrated that the NiO nanoparticles are evenly distributed throughout the Bentonite surface and that the NiO@Bentonite nanocomposites have a high specific surface area and rich pore structure. The following report details the investigation of this catalyst for the preparation of 1, 8-dioxodecahydroacridine heterocycles in a one-pot, three-component reaction of aromatic aldehydes, dimedone, and aniline. After the conditions were optimized, the results demonstrated that this reaction could be carried out in an aqueous medium with a good yield.

"Evaluation of spinel ferrites magnetic nanoparticles based hyperthermia: in-vitro study"

This study is an attempt to compare the hyperthermia and antimicrobial activity of three members of the family of spinel ferrite magnetic nanoparticles (XFe2O4, where X = Mg, Cu, and CO) MNPs. Spinell ferrite of MgFe2O4, CuFe2O4, and CoFe2O4 were prepared via sol–gel method. Structural and morphological shapes were investigated by different techniques X-ray diffraction X-ray powder diffractometer (XRD), Fourier transformed infrared spectroscopy (FTIR), and (Transmission electron microscope) TEM. Magnetic properties were examined by vibrating sample magnetometer (VSM). The in vitro test was conducted on cervical Hela cells using an MTT assay. Finally, the antimicrobial activity was tested on Staphylococcus aureus, Bacillus subtlus, and Escherichia coli using a clearing inhibition zone. XRD results confirmed the crystalline nature of MgFe2O4, CuFe2O4, and CoFe2O4. VSM results showed a high maximum saturation (Ms = 44.87 emu/g) of CuFe2O4 which is greater than that of CoFe2O4 and MgFe2O4 (18.221 and 18.669) emu/g, respectively. MTT assay revealed that high cell death was detected on Hela cells of CuFe2O4 compared to that of MgFe2O4 and CoFe2O4. The anti-microbial study showed that the prepared spinel magnetic nanoparticles possessed antimicrobial activity due to the release of Mg, Cu, Co, and Fe ions. Results showed that the CuFe2O4 could be a good spinel ferrite for medical application with antimicrobial activity and generate heat (hyperthermia, anti-cancer material).

Synthesis and characterization of (Ba2Zn2Fe12O22)1−x(NiFe2O4)x ferrite composites for antenna applications

A series of (Ba2Zn2Fe12O22)1−x(NiFe2O4)x ferrites (x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) were successfully synthesized by one-pot coprecipitation route. XRD analysis reveals the formation of Ba2Zn2Fe12O22 and NiFe2O4 composite after sintering calcined precursor powder at 1200 °C/ 4 h. Densification behaviour was evaluated by Archimedes’ principle. Field emission scanning electron microscopy was used to study morphological characteristics. Room temperature magnetization behaviour was evaluated using a vibrating sample magnetometer. In composite, it was observed that the saturation magnetization (Ms) and coercivity (Hc) increased with increasing NiF content. With the increase of NiF in the composite, the permittivity (ε) decreased from 28.6 (for x = 0.2) to 13.6 (for x = 0.8) with the corresponding decrease in dielectric loss (tanδε) at 100 MHz. The permeability (μ) also decreased from 21.3 (x = 0.2) to 17.9 (x = 0.8) with the associated decrease of the magnetic losses (tanδμ) at 100 MHz. Miniaturization factor (n) of 19.2 and characteristic impedance of 1.1 were obtained for x = 0.4 composition at 100 MHz along with low dielectric loss factor (tan δε/ε) and magnetic loss factor (tan δµ/µ). The ferrite resonator antenna was fabricated using FR4 as substrate and ferrite pellet as magneto-dielectric resonator material. The antenna characteristics parameters reflection loss S (1,1) and voltage standing wave ratio (VSWR) were measured by vector network analyser (VNA)

Green Capping Agents and Digestive Ripening for Size Control of Magnetite for Magnetic Fluid Hyperthermia

Background: Magnetite is the most recognized iron oxide candidate used for various biological applications. Objective: This work is a complete study that addresses the synthesis of magnetic nanoparticles and investigates the feasibility of using green tea and ascorbic acid as capping agents. Methods: Synthesis of magnetite by two wet chemical methods namely: coprecipitation and solvothermal methods. The samples were characterized using X-ray diffraction (XRD), transmission electron microscope (TEM), and vibrating sample magnetometer (VSM). Results: The results reveal the impact of coating on the size and morphology of the particles. The study also proves that autoclaving the samples prepared by coprecipitation results in smaller particle size and narrower size distribution due to digestive ripening. In addition, a novel and facile methodology for coating magnetite with polyethylene glycol is presented. The potential of the particles to be used for magnetic fluid hyperthermia is assessed by measuring the specific absorption rate (SAR) of the samples. Conclusión: The results show that all the prepared magnetite samples showed a promising capacity to be used as magnetic fluid hyperthermia agents.

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.

Adsorptive Removal of Pb2+ from Aqueous Solution by Magnetic Biodegradable and Polymeric Cellulose/Nylon 6@Fe3O4 Nanocomposite Encapsulated with Chitosan

A novel polymeric magnetic nanocomposite adsorbent (CNCs/N6@Fe3O4–CT) of low-cost, biodegradable, and ultra-permeable materials was prepared and characterized. The adsorbent was used to evaluate the effect of influencing factors and competitive ions on the adsorption of Pb2+ ions. The obtained data was fitted to equilibrium and thermodynamic models. The chemical and structural features of the adsorbent were investigated using a range of characterization techniques, including a vibrating sample magnetometer (VSM), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). FTIR confirmed the presence of OH–, –NH2, and FeO sorption sites. SEM micrographs revealed presence of visible pores on the surface of the adsorbent, while VSM established a magnetic strength of 26.90emu/g. The adsorption data fitted well with Langmuir isotherm, whereas the adsorption kinetics followed the pseudo-second-order kinetic model with a coefficient of determination (R2 >0.98). The thermodynamic parameters indicated that the adsorption of Pb2+ was exothermic and spontaneously adsorbed. The adsorption process was dominated by a chemical process with E >10kJ/mole, indicating an ion exchange process. The results established that the synthesized CNCs/N6@Fe3O4–CT nanocomposite adsorbent is viable for the removal of metal ions from aqueous solutions and has the potential for optimization and scale-up.

Synthesis, evaluation, and biocompatibility study of magnetite nano particles in normal cells and cancer cells for health care application

Magnetic nanoparticles have been synthesized in a very simple and economical way by the co-precipitation method, where the effect of molar concentrations of ferric chloride anhydrous (FeCl3) and iron (II) sulphate heptahydrate (FeSO4.7 H20) on magnetite synthesis has been investigated. Also, a detailed study was conducted to study the effect of magnetite and hematite on both normal and cancerous cell lines. After this, the magnetic nanoparticles obtained were analyzed by x-ray Diffraction (XRD), scanning electron microscope (SEM) - energy dispersive x-ray (EDX), Fourier transform infrared spectroscopy (FTIR), zeta potential, vibrating sample magnetometer (VSM), atomic force microscopy (AFM), MTT test, and cell apoptotic assay. The XRD peaks for magnetite were easily discernible in the final formulation. SEM images showed round particles in nano ranges, and FTIR peaks showed the presence of magnetite. Zeta potential showed surface charges. VSM showed the magnetic property of magnetite, and AFM confirmed SEM images. It can be concluded that magnetic nanoparticles were synthesized by the co-precipitation method using an optimized molar concentration of reagents. Also, the necessity of coating uncoated magnetic nanoparticles can be seen from the MTT assay. Cell apoptotic assays have shown that synthesized magnetite nanoparticles have shown potential apoptotic activity on cancer cell lines.

Magnetic Properties of Borided Co-Cr-Mo Alloy

The magnetic properties of a borided Co-Cr-Mo alloy were studied in this work. The boron process was performed by the powder pack method with Ekabor HM and Ekabor III boron sources at 1123 and 1323 K for 9 h. The magnetic properties were characterized with a vibrating sample magnetometer (VSM). The results show that the non-magnetic Co-Cr-Mo alloy has a low magnetization with the boriding process. In addition, the saturation magnetization (Ms) varies with the boron source and temperature.