Ferrite Composites Research Articles

Magnetoelectric coupling and energy harvesting in 2/3Pb(Mg1/3Nb2/3)O3-1/3PbTiO3: CoFe1.97RE0.03O4 (RE = La3+ and Eu3+) composites

The ferroelectric-ferromagnetic composites are attracting attention as the new generation multifunctional device applications owing to the strong magnetoelectric coupling due to piezoelectric and magnetostrictive constituents. This study focuses on coupling between the piezoelectric 2/3Pb(Mg1/3Nb2/3)O3-1/3PbTiO3 and the rare earth (RE = La3+ and Eu3+) substituted magnetostrictive cobalt ferrite (CoFe1.97RE0.03O4) composites. The M−H loop and P-E loop measurements confirm the ferromagnetic and ferroelectric nature of the composites, respectively. The well-saturated hysteresis loop suggests the ferromagnetic nature of composites ascribed to the ferromagnetic ferrites. The P-E loop becomes broad as the ferrite concentration increases, owing to the conducting nature of the ferrite. In both sets of composites, the 80:20 composition shows the maximum αME value, which is ∼ 4.104 mV/cm-Oe for 80PMN-PT:20CFLO and ∼ 3.142 mV/cm-Oe for 80PMN-PT:20CFEO at 1 kHz. Besides, at the resonance frequency (fr) the 90:10 compositions show a higher αME, ∼3118 mV/cm-Oe at 288 kHz for 90PMN-PT:10CFLO and ∼ 2580 mV/cm-Oe at 282 kHz for 90PMN-PT:10CFEO. The energy harvesting application is demonstrated by placing the sample atop the rotating AC axial exhaust fan. The 80PMN-PT:20CFLO composite produced the highest peak-to-peak AC voltage (Vpp) of about 4.24 V. The outcomes of this study show that the studied composites can be employed effectively for energy-harvesting applications.

Investigation of Magnetic, Electrical and Optical Properties of Soft-Hard Ferrite Composite Synthesized by Sol-Gel Technique

Soft and hard composites of ferrites with compositional formula (NiFe2O4)100-x – (BaFe12O19)x (where x = 0,20,50,60,80,100) were prepared using sol-gel method. The samples were calcined individually at 900 °C and composites in the required proportions were sintered at 1100 °C in a conventional furnace. The coexistence of NiFe2O4 and BaFe12O19 composites has been confirmed by the X-ray diffraction studies and found to be without any impurities. Rietveld analysis of X-ray diffractograms corroborates hexagonal phase with P63/mmc space group for Barium hexaferrite and cubic phase with Fd-3m:2 space group for Nickle ferrite. The surface morphology was investigated by scanning electron microscopy (SEM), and the micrographs are observed to indicate well distributed grains in the exchange coupled composites. Grains of nano-size about 100–300 nm are formed for the composites. The magnetic properties have been studied by VSM and electric properties were studied by measuring the dielectric constant at room temperature. UV; FTIR studies of the samples are exhibiting fundamental absorption bands.

Synthesis of magnetic MFe2O4@PC (M = Fe, Cu, Co, and Mn) composites and application of heterogeneous photo-Fenton efficient removal of metronidazole under visible light

Nanoscale magnetic spinel ferrite composites with the general formula MFe2O4@PC (M = Fe, Cu, Co, and Mn; PC = biochar) were prepared by a facile impregnation and pretreatment method. MFe2O4@PC particles were deliberated by X-ray Diffractometer (XRD), Fourier Transform Infrared (FTIR), Scanning Electron Microscope (SEM), Brunauer–Emmett–Teller adsorption–desorption isotherm (BET), X-ray Photoelectron Spectroscopy (XPS) and Vibrating Sample Magnetometer. The results showed that MFe2O4 coating, which is evenly distributed on the surface of HNO3-pretreated biochar, can provide more active sites to enable MFe2O4@PC to be activated by visible light. The XRD confirmed that the crystallite sizes of MFe2O4 ranged from 10.0 to 27.9 nm. With the help of surface-OH, PCoF has a rapid adsorption performance on metronidazole (MNZ) and can degrade 99% of MNZ within 20 minutes at an optimal pH of 3.0. Meanwhile, the PCuF composites showed excellent photo-Fenton catalytic performance for the degradation of MNZ under neutral pH conditions, and 96.0% of MNZ (300 mg/L) could be removed within 120 min. This study confirmed OH is the main reactant, while O2− and h+ contributed to the degradation of MNZ during photocatalysis. MFe2O4@PC composite can be separated easily by an external magnetic field. The synthesized PCoF was reused for 5 cycles and it was clear that it had no significant loss, indicating its excellent ability to remove MNZ from wastewater.

Investigation of calcium substitution on magnetic and dielectric properties of Mg–Zn nano ferrites

In this work, an efficient, cost-effective, and less time-consuming citrate precursor wet chemical approach was employed to prepare a series of Calcium (Ca) doped Magnesium–Zinc ferrite of composition Mg0.4Zn0.6-xCax Fe2O4 (0.0 ≤ x ≤ 0.6). X-ray diffraction (XRD), Scanning electron microscopy (SEM) with Energy dispersive X-ray (EDX) analysis confirmed the spinel structure and nanometric size of the particles. Williamson-Hall (W–H) plots were drawn by making use of XRD data and calculated values of lattice strain were found in the range (3.00 × 10−3 to 9.09 × 10−3) for various concentrations of calcium. The cubic spinel structure of produced ferrites was also verified by three active Raman modes (A1g, Eg, and T2g). In the Vibrating sample magnetometer (VSM) study, an “S” shape curve shows the low values of coercivity for all the samples in the range 59–105 Oe. For all Ca concentrations, the dielectric loss tangent values were evaluated to be extremely low 0.03 to 0.18 at 1 MHz frequency. The highly magnetic nature and very low value of loss factor make this prepared nanoferrite material best suited for the manufacturing of high-frequency application devices.

Preparation of microcrystalline graphite/zinc ferrite composites with enhanced and tunable electromagnetic wave absorption using a high-temperature ball milling method

Microcrystalline graphite (MG)/zinc ferrite (ZFO) composites were prepared by a high-temperature ball milling method. The magnetic and microwave absorption properties of MG/ZFO composites were analyzed in the frequency range of 2.0–18.0 GHz. The results showed that MG has a favorable impact on the microwave absorption capacity of ZFO. The composites containing 10 wt% MG had a minimum reflection loss of −62.90 dB, which is almost a factor of 12 higher than for pure ZFO, and their effective absorption bandwidth (EAB, RL<−10 dB) covers frequency range of 5.84–7.92 GHz for a matching thickness of 3.9 mm, and for a matching thickness of 1.8 mm, the EAB covers frequency range of 12.87–17.70 GHz. A probable mechanism of microwave absorption for MG/ZFO composites is based on a synergistic combination of dielectric and magnetic losses. The attractive properties of prepared composites indicate that they are promising and competitive materials for use in microwave absorption.

Anticorrosive Polypyrrole/Barium Ferrite (PPy/BaFe12O19) Composites with Tunable Electrical Response for Electromagnetic Wave Absorption and Shielding Performance

Anticorrosive Polypyrrole/Barium Ferrite (PPy/BaFe12O19) Composites with Tunable Electrical Response for Electromagnetic Wave Absorption and Shielding Performance

Study of Defect-Induced Chemical Modifications in Spinel Zinc-Ferrites Nanostructures by In-Depth XPS Investigation

Spinel zinc ferrite nanomaterials with exceptional physiochemical properties are potential candidates for various applications in the energy and environmental fields. Their properties can be tailored using several methods to widen their applications. The chemical combustion approach was followed to prepare the spinel zinc ferrite nanomaterials, which were then subjected to thermal treatment at a fixed temperature. Thermal heat treatment at a fixed temperature was used to evaluate the phase and morphological characteristics of the prepared spinel zinc−ferrite nanocomposites. Various techniques were employed to examine the samples, including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). XPS and X-ray−induced Auger electron spectroscopy were used to extensively examine the surface characteristics of the zinc−ferrite. To study the actual chemical states of the synthesized spinel zinc ferrite nanomaterials and the defects created during the thermal treatment, an extensive investigation of the kinetic energy of the X-ray−induced Zn L3M45M45 and Fe L3M45M45 was conducted. Finally, a detailed analysis of the Wagner plot using the modified Auger parameter was performed to verify the exact chemical states of Zn and Fe. Thus, the findings of the investigation show that XPS is a promising and powerful technique to study the composition and chemical states of spinel zinc ferrites, providing an understanding of changes in their properties for functional applications.

Understanding the effect of synthesis and sintering temperature on the functional properties of barium titanate/cobalt ferrite composites

To investigate the effect of synthesis procedure and sintering temperature on the functional properties of perovskite/spinel ceramics, BaTiO3/CoFe2O4 composites were prepared by thermal decomposition, coprecipitation, and microemulsion method, and sintered at 1150?C and 1300?C. The phase composition and morphology of as-prepared powders as well as sintered ceramics were thoroughly examined by X-ray powder diffraction (XRPD) and scanning electron microscopy (SEM) coupled with electron dispersive spectroscopy (EDS). The dielectric and ferroelectric measurements were performed in detail. Generally, the samples sintered at 1300?C had better performances than those sintered at 1150?C. The composite synthesized by thermal decomposition and sintered at 1300?C stands out among other prepared BaTiO3/CoFe2O4 ceramics, owing to high stability in the wide frequency range and low leakage currents. The obtained results indicate that such composite might be successfully applied as a functional multiferroic.

Enhanced detoxification of Cr6+ by Shewanella oneidensis via adsorption on spherical and flower-like manganese ferrite nanostructures.

Maximizing the safe removal of hexavalent chromium (Cr6+) from waste streams is an increasing demand due to the environmental, economic and health benefits. The integrated adsorption and bio-reduction method can be applied for the elimination of the highly toxic Cr6+ and its detoxification. This work describes a synthetic method for achieving the best chemical composition of spherical and flower-like manganese ferrite (MnxFe3-xO4) nanostructures (NS) for Cr6+ adsorption. We selected NS with the highest adsorption performance to study its efficiency in the extracellular reduction of Cr6+ into a trivalent state (Cr3+) by Shewanella oneidensis (S. oneidensis) MR-1. MnxFe3-xO4 NS were prepared by a polyol solvothermal synthesis process. They were characterised by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectrometry (XPS), dynamic light scattering (DLS) and Fourier transform-infrared (FTIR) spectroscopy. The elemental composition of MnxFe3-xO4 was evaluated by inductively coupled plasma atomic emission spectroscopy. Our results reveal that the oxidation state of the manganese precursor significantly affects the Cr6+ adsorption efficiency of MnxFe3-xO4 NS. The best adsorption capacity for Cr6+ is 16.8 ± 1.6 mg Cr6+/g by the spherical Mn0.22+Fe2.83+O4 nanoparticles at pH 7, which is 1.4 times higher than that of Mn0.8Fe2.2O4 nanoflowers. This was attributed to the relative excess of divalent manganese in Mn0.22+Fe2.83+O4 based on our XPS analysis. The lethal concentration of Cr6+ for S. oneidensis MR-1 was 60 mg L-1 (determined by flow cytometry). The addition of Mn0.22+Fe2.83+O4 nanoparticles to S. oneidensis MR-1 enhanced the bio-reduction of Cr6+ 2.66 times compared to the presence of the bacteria alone. This work provides a cost-effective method for the removal of Cr6+ with a minimum amount of sludge production.

Retracted: Research on the Formation Mechanism of MgO and Al2O3 on Composite Calcium Ferrite Based on DA-RBF Neural Network.

[This retracts the article DOI: 10.1155/2022/4327969.].

Synthesis and characterizations of nickel doped Co-Zn-Y ferrites

The Nickel substituted Cu-Co-Zn-Ce nano ferrites, Zn0.15Co0.45Cu0.40-xNix Fe1.85Ce0.15O4 with x=0, 0.1, 0.20, 0.30, 0.40, were synthesized using the coprecipitation technique. The sample were sintered at 900 ℃ for 5h. The structural, electrical, dielectric and magnetic properties of all the prepared samples were characterized by XRD, SMU2401, UV-Vis and FTIR. The powder X-ray diffraction patterns of all the prepared samples confirmed the formation of single-phase cubic spinel structures. These samples further characterized for the electrical properties by using two-probe type method. The DC resistivity of all the ferrite composition decreased as the temperature increased, showing their semiconductor nature. UV-Vis and FTIR confirmed the substitution of nickel in Cu-Co-Zn-Ce ferrites. From UV-Vis it is observed that the optical band gap changes from 3.9 eV to 5.3 eV with addition of Ni. FTIR analysis revealed that a strong variation on tetrahedral absorption frequency band is present which is due to the replacement of Ni on Cu. All these results suggested that these materials can be used for wastewater treatment.

Fabrication of low-cost p-n heterostructure room temperature LPG sensing properties of Polyaniline–Copper ferrite composite

Fabrication of low-cost p-n heterostructure room temperature LPG sensing properties of Polyaniline–Copper ferrite composite

Microstructural and magneto-optical properties of Co1-xNix Fe2O4 nanocomposites for hyperthermia applications

Magnetic hyperthermia-induced ferrite nanoparticles influenced by an external alternating magnetic field (AMF) are actively being pursued as a therapeutic tools for treating cancer tumor tissue. This work reports a combined experimental and computational study of pristine and Ni-doped cobalt ferrite. Specifically, cobalt ferrite (CoFe2O4) nanoparticles doped with nickel ions (Co1-xNix Fe2O4) with 0≤x≤0.6 have been synthesized by in-situ sol-gel protocol to enhance the microstructural and magneto-optical properties. The formulated samples were evaluated using various characterization techniques. To further accentuate the properties of the synthesized samples, we used first-principles density functional theory (DFT) calculations to model the various cobalt ferrite compositions. The obtained results from DFT are in good pact with the structural, optical and the magnetic properties as observed in the experiment. Hence, our results demonstrate synthesis protocols and band-engineering routes to enhance the microstructural and magneto-optical properties of cobalt ferrite for magnetic hyperthermia applications.

Review of ferrite-based microwave-absorbing materials: Origin, synthesis, morphological effects, dielectric/magnetic properties, composites, absorption mechanisms, and optimization

With the advancement and up-gradation of wireless technology, people worldwide are surrounded by microwaves, however, with the brighter side comes the darker side too. These microwave/electromagnetic wireless signals interfere with the environment/mankind and are referred to as electromagnetic interference (EMI)/electromagnetic or microwave pollution. Microwave/electromagnetic absorbers are used to mitigate this EMI or electromagnetic pollution. Researchers have been working on microwave absorbents of different kinds to save humans, their gadgets, electronically printed cards, etc. to create a healthy and radiation-free environment. Recently, there is an advancement in different forms of ferrite absorbers. This review presents a description of what are ferrite-based microwave absorbers, the preparation method of absorbers, the working principle, and detailed insights involving necessary models and mechanisms regarding microwave absorption. It also encapsulates the description of how the ferrite composition, morphology, doping, reflection loss peaks, and matrix account for optimizing the performance of the absorbers. The history, origin, and ancestral use of microwave absorbers are mentioned, and how technological needs lead to advancement in ferrite microwave absorbers has also been discussed. A picture is portrayed of what are microwaves, their potential hazards, and how these hazards should be taken care of with the help of ferrite microwave absorbers.

Evaluation of molecular transport mechanism and interfacial interactions in doped ferrite rubber composites

Nickel ferrites (NIFs) come under the class of soft ferrites or transformer ferrites, which are highly demanding in the electronics industry and possess usual low conductivity and ferromagnetic properties, which results in decreased eddy current losses, good electrochemical stability, catalytic action, and abundance in nature. We discuss the synthesis, characterization, and impact of synthesized NIF fillers on the mechanical and solvent transport characteristics of rubber composites. Doped ferrite composites made of natural rubber and nitrile rubber were cured at various temperatures, and the solvent swelling properties of composites containing differently doped NIFs were examined in aromatic solvents like toluene. Properties of both rubber composites were examined, including their morphology, solvent uptake, diffusion coefficient, transport mechanism, and thermal stability. Natural rubber composites found to have better swelling properties than that of nitrile rubber composites. The solvent uptake was reduced with increase in filler loading also, the increase in sorption temperature increases the swelling rate in both systems. Theoretical calculations and modelling clearly state that the diffusion mechanism is due to the polymer swelling as well as polymer relaxation.

Microwave Absorption Properties of FeSiCr/MnZn Ferrite Composites Prepared by Two-Step Synthesis

Microwave Absorption Properties of FeSiCr/MnZn Ferrite Composites Prepared by Two-Step Synthesis

Microwave absorption performance enhancement of NiFe2O4/GNs composite with hollow hexagonal-like structure

It is a major aspect in the field of absorbing materials to obtain composite absorbing materials with prominent absorbing properties through shape design. In this paper, a hollow hexagonal NiFe2O4/GNs composite absorbing material was prepared by a simple hydrothermal method. The test results show that the minimum reflection loss of the composite can reach −57.4 dB at the low frequency of 6.08 GHz, and the corresponding thickness is 2.9 mm; When the hydrothermal reaction temperature is 200 ℃, the maximum effective absorption bandwidth is 3.12 GHz, and the thickness is as thin as 1.1 mm. With the increase of hydrothermal reaction temperature, the morphology of nickel ferrite gradually changed from round rod to hollow hexagonal prism, and the microwave absorption characteristics of the composite also varied and adjusted. This paper provides the preparation process of NiFe2O4/GNs composites with controllable morphology, and possesses a certain reference for the study of the interaction mechanism of ferrite and graphite nanosheets composite microwave absorbing materials. In addition, the sample has excellent microwave absorption performance in the low-frequency band, while the current wave absorption band of ferrite composites is mainly in the high-frequency band, so the sample has great research and development potential in the field of low-frequency microwave absorbing materials.

Study of morphology and magnetism of MnFe2O4–SiO2 composites

Mixed magnetic composites of manganese ferrite and cristobalite (MnFe2O4–SiO2) were produced by the solid-state reaction method, using as starting materials in natura ores found in the state of Rio Grande do Norte – Brazil. Based on the stoichiometric proportions of the precursor ores, various composites in the form of powders and pellets were synthesized at a temperature of 1200 °C/12h under ambient atmosphere. Samples in the form of pellets were made at compression pressures of 370 and 740 MPa to investigate the effect of pressure on the physicochemical, and dielectric properties of the material. Structural, morphological and magnetic analyses were studied for the series of samples. X-ray diffractogram (XRD) results confirmed the formation of the mixed spinel phase MnFe2O4 with cubic symmetry and space group Fd-3m:1, together with peaks corresponding to SiO2–cristobalite. The Rietveld refinements identified a predominance of about 90% of the MnFe2O4 phase with crystallite variations of 130–190 nm due to the effect of compaction pressure. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and transmission electronic microscopy (TEM) mappings show clusters of triangular crystals in the pellets series. Magnetic hysteresis cycles at room temperature show a fast magnetization saturation (MS) response in a field of ∼4 kOe, with parameters dependent on the size and shape of the crystallites. The magnetically soft ferrites exhibited very low coercive field values. The hysteretic curves measured at 5 K showed a significant gain in the MS of ∼30 emu/g. Analyzes of magnetization as a function of temperature identified a blocked regime with a maximum ∼97 K (powder) and ∼170 K (pellets), and an irreversibility of the ZFC–FC curves up to room temperature. An indication of a spin-glass (SG) like state close to 20 K can also be seen in these results. Dielectric characterization of the pellets was performed from 1.0 to 8.5 GHz, and presented well-defined behavior, where real permittivity can be highly related to Rietveld refinement of XRD, and SEM/EDS results. This research suggests the feasibility of producing manganese ferrite composites directly from minerals, without the use of high-purity chemical reagents, allowing their obtainment on a large scale for commercial use.

Preparation and characterization of electromagnetic wave absorbing material from polymetallic vanadium titano-magnetite (VTM): Oriented phase transformation underlying formation mechanism

Polymetallic vanadium titano-magnetite (VTM) is recognized as one of the most refractory mineral resources because of its multiple-element composite symbiosis feature. Conventional carbothermic reduction and smelting separation treatment are characterized by high energy consumption and large greenhouse gas emissions. Considering the material attribute, an alternative and clean utilization of refractory VTM via the pyrometallurgically oriented phase transformation in air atmosphere to prepare the composite electromagnetic wave absorbing material was proposed for the first time in this work. The theoretical foundation of the oriented composite material design, phase transformation, microstructure and interfacial element migration, magnetism, electromagnetic properties, and wave absorbing properties were investigated via thermodynamic calculations, XRD, XPS, optical microscope, SEM‒EDS, VSM, and VNA analyses. Theoretical calculations indicated that the formation of composite ferrites was thermodynamically feasible over 1085 °C. In the oriented phase reconstruction, the symbiotic structure of the VTM was reconstructed via MnO2 addition at 1150 °C, and almost all the Fe, Mn, Ti, and V were concentrated in the composite ferrites, in which the Ti and V were doped in the octahedral structure (B site) of spinel-type crystalline structure. The as-purified composite ferrite material from the VTM+80%MnO2 mixture roasted at 1150 °C for 2 h showed good electromagnetism performance. A minimum RL peak of −50 dB was obtained at a veneer thickness of 11 mm, and the RL value less than −20 dB had a big frequency bandwidth of 9 GHz (frequency range of 8 GHz–17 GHz). It's inferred that this low-cost and abundant composite ferrite material can be economically applied in the construction industry. This work provided a clean and higher-value application of abundant refractory polymetallic VTM resources.

Magnetic Zinc Oxide/Manganese Ferrite Composite for Photodegradation of the Antibiotic Rifampicin.

In this study, a composite of zinc oxide and manganese ferrite was synthesized using co-precipitation and hydrothermal routes, to be used as photocatalysts in reactions with UV/Vis light source. The synthesized materials were characterized by FTIR, XRD, and SEM, where it was possible to verify the efficiency of the syntheses performed, through the identification of the resulting phases, the evaluation of the structural morphology of the particles, and the analysis of the detachments of the main vibration bonds present in these materials. The composite ZnO/MnFe2O4 was used in photodegradation reactions of the antibiotic rifampicin, with catalyst dosage of 0.20; 0.40, and 0.60 g and 10 ppm of rifampicin, reactions using pure ZnO as a catalyst were also performed as a comparative parameter of the influence of MnFe2O4 in this system. The composite ZnO/MnFe2O4 showed a maximum percentage of rifampicin decontamination of 94.72% and ZnO, 74.20%using 0.20 g of photocatalyst after 90 min, which indicates a positive influence on this process. The solution treated with ZnO/MnFe2O4 was subjected to magnetic field induction for attraction and consequently accelerated removal of the solids present, successfully, compacting for the application of ZnO/MnFe2O4 to be presented as a promising material for decontamination of emerging pollutants through photocatalytic reactions.