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An analysis to the characteristics of Co, Mg and Cu ferrites that were prepared using sol–gel method and annealed at 800∘C for 1 hour, performed using X-ray diffraction and Raman spectroscopy for structural characteristics, while the Vibrating Sample Magnetometer (VSM), was used for the magnetic characteristics. The X-ray analysis of both cobalt and magnesium ferrites shows a reverse crystal structure of a cubic spinel, while copper ferrite shows a tetragonal crystal structure characteristic at this annealing temperature. The lattice constant (a) was found to be a=8.186 for CoFe2O4, a=8.199 for MgFe2O4 and a=5.969 for CuFe2O4. The Raman spectrum confirms a spinel crystalline form of the prepared ferrites where a likely distribution of cation is indicated at the tetrahedral and octahedral sites. The peaks of the Raman shift appear between 200–800cm−1. These peaks indicate the formation of ferrites. The hysteresis loop of CoFe2O4 indicates a hard magnet material. Cu ferrites have relatively lower remnants and magnetocrystalline anisotropy, which indicates soft magnetic characteristics even though it showed higher coercivity. The squareness ratio (Mr/Ms) values varied between 0.52, 0.13 and 0.57 for CoFe2O4, MgFe2O4 and CuFe2O4, respectively. These insights highlight the possibility of tuning the properties of ferrites using a cost-effective sol–gel method. [ABSTRACT FROM AUTHOR]

In this work, CFO/MWCNTs/PVDF and BFO/MWCNTs/PVDF composites are prepared and the comparative analysis of electrical properties and electromagnetic interference (EMI) shielding performance of both type of composites are investigated. The dielectric and conductivity characteristics are observed with varying ferrite concentration, frequency, and temperature. Ferroelectric properties are also obtained at 6 kV/cm field and EMI shielding behavior is observed in 8–12 GHz frequency range. Results exhibited that the studied properties of the composite enhances with increasing ferrite concentration that attributed to increased amount of magnetic nanoparticles. Cobalt ferrite (CFO) filled polyvinylidene fluoride (PVDF) composite is showing better properties as compared to barium ferrite (BFO) filled PVDF composites. The mechanism involve for this behavior is discussed herein. [ABSTRACT FROM AUTHOR]

The transition from external to internal oxidation of a binary Fe-10Cr alloy has been investigated in Fe/FeO Rhines pack (RP) and H2/H2O between 850 and 900 °C. Internal oxidation is facilitated by increasing temperature and presence of water vapor. A classical Wagnerian diffusion analysis predicts external oxidation for ferritic (BCC) Fe-10Cr and internal oxidation for austenitic (FCC) Fe-10Cr. The α-to-γ transformation is demonstrated to be the primary factor promoting internal oxidation in Fe–Cr around 900 °C. Water vapor is believed to promote internal oxidation due to a higher reactivity of H2O compared to O2 and higher preferential adsorption of the H2O molecule. [ABSTRACT FROM AUTHOR]

This study investigates Beam Line Absorbers (BLAs) for the Hefei Advanced Light Facility (HALF). A ferrite-based BLA prototype was developed, demonstrating high-power handling capacity up to 10 kW, ultra-high vacuum performance better than 6. 5 × 1 0 − 1 0   mbar, and high absorption efficiency in critical frequency ranges. Subsequently, more compact designs with reduced longitudinal length were explored, investigating ferrite-only, silicon carbide (SiC)-only, and hybrid configurations through RF simulations. Based on preferred absorption efficiency, ferrite-only and hybrid BLA structures were further analyzed under high-power conditions. Referencing test results, multiphysics simulations were conducted under 3 kW absorbed power. The hybrid design, comprising two rings of ferrite tiles and one ring of SiC tiles, improved the temperature distribution of the absorbing materials. Extrapolating to 11 kW absorbed power, this design reduced the maximum temperatures on absorbing tiles by up to 40 ° C compared to the ferrite-only design. The hybrid design offers a balanced solution that combines effective HOM damping with enhanced thermal performance, improving the long-term operational stability of BLAs. [ABSTRACT FROM AUTHOR]

Magnesium ferrites doped with lanthanum (MgLaF) and cerium (MgCeF) were synthesized according to the combustion method. These ferrite-based nanoparticles showed improved adsorption properties for uranium ions. The maximum capacity of 138.95 and 152.39 mg/g were achieved at pH 5 after 30 min of contact with the MgLaF and MgCeF nanoparticles. The outcomes demonstrated that the nanoparticles have a high adsorption affinity for uranium ions (θ ≥ 0.9396). This adsorption affinity was not significantly affected by the presence of other ions, where the amount of uranium adsorbed from granite leach liquor on MgLaF and MgCeF reached 122.7 and 134.8 mg/g. [ABSTRACT FROM AUTHOR]

The dominant treatment process for removing heavy metals from industrial wastewater is chemical neutralisation precipitation using lime milk as a precipitation agent, resulting in a highly voluminous hydroxide sludge with a low heavy metal concentration. These sludges are predominantly landfilled, and the metals are lost to the circular economy. At the same time, metals are urgently needed as raw materials. A new approach is represented by the low-pressure, low-energy Specific Product-Oriented Precipitation process (SPOP). This approach, however, requires the adjustment of various reaction parameters for optimal operation. This study presents the impacts of the stirring rate during the reaction and the Fe concentration in the solution on the recovery of Cu from Cu-enriched electroplating wastewater. Three different recovery options are described: Option (1), the formation of CuO; Option (2), the generation of brochantite, a Cu-hydroxysulphate; and Option (3), the incorporation of Cu into ferrite. Tenorite (CuO) is precipitated at 40 °C reaction temperature at a low stirring rate of 100–200 rpm. At an accelerated stirring rate of 400–500 rpm, brochantite (Cu4(OH)6SO4) is formed. With high Fe concentrations and a molar ratio of Cu:Fe of 1:2, Cu-ferrite (CuFe2O4) is the precipitation product. In any case, the achieved recovery rates in the treated wastewater are better than 99.9%. [ABSTRACT FROM AUTHOR]

In the current work, MnxZn1−xLa0.1Fe1.9O4 ferrite nanoparticles were prepared using a solid-state reaction, with x values of 0, 0.1, 0.3, 0.5, 0.7, and 1. The structure, morphology, optical, magnetic, and dielectric characteristics of the prepared samples were characterized using X-ray Diffraction (XRD), Fourier Transformed Infrared Spectrometer (FTIR), Scanning Electron Microscopy (SEM), UV-Vis spectrophotometer, Vibrating Sample Magnetometer (VSM) and impedance analyzer. XRD and FTIR spectra assured the formation of the cubic spinel phase structure as well as tetrahedral and octahedral bonding in the synthesized samples. SEM analysis of the surface morphology revealed irregular and semi-spherical shapes. The prepared samples' elements were confirmed to be present based on their chemical composition by the EDX analysis. The Kubelka-Munk function was used to calculate the optical band-gap energy Eg based on the near-infrared (NIR) and visible (VIS) reflectance spectra, which are dependent on Mn dopant ion concentration. The VSM findings demonstrate that the characteristics of the samples transformed gradually from antiferromagnetic to ferromagnetic behavior with increasing Mn content. The dielectric results exhibit that the doping of Mn ions decreases the dielectric constant and dielectric loss and increases the resistivity. The physical properties of MnxZn1−xLa0.1Fe1.9O4 nanoparticles, such as their low power losses, coercivity, high resistivity, permittivity, and saturation magnetization, make them suitable for many applications, from biomedical to electronic devices. [ABSTRACT FROM AUTHOR]

Optical vortex induced forward transfer (OV-LIFT) allows the crystallization of magnetic nanoparticles enabling the fabrication of a 2-dimensional array of monocrystalline structures with a high spatial resolution. We herein investigate the optimum experimental conditions, such as the viscosity range of the donor and the energy range of the optical vortex pulse required for the crystallization of magnetic nanoparticles through a cavitation processes, including the flight dynamics of donor. [ABSTRACT FROM AUTHOR]

Herein, sol gel method was used to prepare titania coated manganese ferrite nanocomposite (TMFN) for wastewater treatment. The prepared TMFN nanocomposite was characterised using FTIR, SEM XRD, VSM, EDX, and BET techniques. The characterisation studies confirmed the formation of the nanocomposite and gave good information about its morphology. Batch adsorption method was applied to determine the optimal adsorption conditions towards Cu(II) and Pb(II) ions. The studied parameters were pH of the solution, contact time, adsorbent amount, initial concentration of ions and temperature. After finding out and applying the optimal adsorption conditions, maximum adsorption capacities of 550 and 460 mg/g were achieved for Cu(II) and Pb(II) ions, respectively. Isotherm and kinetic studies revealed that the current adsorption process is fitted well by Langmuir isotherm and pseudo-second order model. Thermodynamic investigations showed that the adsorption process is energetically favourable and takes place spontaneous with positive enthalpy change. Furthermore, the ability to regenerate and reuse the adsorbent confirmed its sustainability. The prepared nanocomposite could be reused many times with no significant loss in adsorption capacity. [ABSTRACT FROM AUTHOR]

Incorporating suitable wave-absorbing agents into cement and performing appropriate electromagnetic modification is an effective way to realize electromagnetic wave-absorbing. In this paper, cement-based composites were prepared with slag, graphite and ferrite as wave-absorbing agents, and mechanical property test, microstructure test and reflectance test were carried out to investigate the effects of different dopants and sample thickness on the wave-absorbing properties and mechanical properties of cement-based composites. The results show that the cement-based composites have the best wave-absorbing performance when the doping of slag is 30% (mass fraction) and graphite is 5% (mass fraction), and there exists the best matching layer thickness. The reflection loss is -40.84 dB at 2.65 GHz when the thickness is 36 mm. When the cement-based composite is composed of 30% slag, 10% (mass fraction) ferrite, and the matching layer thickness is 36 mm, the cement-based composites have the lowest reflectivity of -26.63 dB at 2.53 GHz. Both slag and ferrite reduce the strength of cement-based composites, and graphite (no more than 5%) is able to fill in mortar pores at the early stage of cement hydration, which enhances early mechanical properties. [ABSTRACT FROM AUTHOR]

Zinc-substituted cobalt ferrites were obtained by a green method using a black grape extract as a reductant and fuel. XRD analysis confirmed the spinel structure of the synthesized ferrites. An increase in the lattice constant is explained by increased Zn content. SEM analysis confirmed changes in surface morphology, whereas FTIR spectra demonstrated the presence of organic species in the samples, which originated from grape extract. The content of Co(II) ions in octahedral sites as a function of the ratio between Fe(III) ions in A- and B-sites was calculated from Mössbauer data. pHPZC rose from 7.85 to 8.13 with an increase in zinc content, indicating a positive charge of the adsorbent surface at natural pH. The adsorption–catalytic properties of the spinel samples were investigated in terms of Congo Red (CR) dye removal. The mechanism of CR adsorption on the ferrite surface includes electrostatic and donor–acceptor interactions with the adsorbent surface. Furthermore, the sample with x(Zn) = 0.4 exhibited the highest degradation rate constant k = 0.102 min−1 in the peroxide oxidation of CR, whereas the sample with x(Zn) = 1.0 exhibited the highest adsorption capacity. The electron transfer between ferrite samples and hydrogen peroxide was evidenced using electrochemical tests. The green-synthesized Co-Zn ferrites demonstrate a big potential as adsorbents/catalysts for water treatment. [ABSTRACT FROM AUTHOR]

Ferrite has been extensively studied due to its wide range of applications. In present work, Li0.4-0.5xZn0.2Mn0.1Mgx-0.1Fe2.4-0.5xO4 (x = 0.1, 0.15, 0.2, 0.25, 0.3) were synthesized by sol-gel auto-combustion method. X-ray diffraction and infrared spectroscopy confirmed the formation of a cubic spinel structure. The lattice constant was found to increase with higher x values, while density, grain size and microstrain decreased correspondingly. The saturation magnetization and coercivity showed slight decreases after Mg doping, whereas the initial permeability slightly increased. The Curie temperature declined from 433 °C at x = 0.1 to 395 °C at x = 0.3. Mg doping also reduced the optimal matching thickness of microwave-absorbing materials to 3 mm. Mg-LiZnMn absorber is lighter in weight than LiZnMn. Notably, the sample with x = 0.15 exhibited excellent absorption characteristics from 8.2 GHz to 13.1 GHz, with a reflection loss (RL) of −32 dB. These findings suggest that an appropriate concentration of Mg doping can enhance the impedance matching of the materials, thereby improving their microwave absorption performance. Highlights: Mg doping can improve the initial permeability of LiZnMn ferrite. Mg doping can reduce the best matching thickness to 3 mm, proper concentration can improve microwave absorption ability of materials. Resonance peaks were observed in permittivity spectra of Mg-doped LiZnMn ferrites. [ABSTRACT FROM AUTHOR]

This research delves into the impact of nickel (Ni), zinc (Zn), and copper (Cu) dopants on the photocatalytic efficiency of iron-silicate glass in wastewater treatment. Physicochemical characterization identified hematite (α-Fe 2 O 3) and spinel configuration of Ni- and Cu-ferrites together with inverse spinel configuration of Zn-ferrite (ZnFe 2 O 4) nanoparticles. 57Fe Mössbauer spectroscopy, combined with Debye temperature analysis, showed a constant total absorption area of Fe³⁺, offering insights into the dynamic behaviour of iron in the silicate matrices. XANES and EXAFS analysis provided insights into the coordination environments of dopants. It revealed that Zn doping leads to Fe³⁺ in a distorted octahedral environment, with Zn-O interactions suggesting the formation of zinc ferrite-like structures. The concordant results were obtained from the XPS spectra. Optical analysis showed a reduction in bandgap energies upon dopant inclusion, suggesting alterations in electronic structures. The photocatalytic performance was assessed through the degradation kinetics of methylene blue (MB) dye and municipal wastewater, showing higher degradation rates in doped samples. Notably, Zn dopant displayed remarkable efficacy in MB degradation with the apparent first-order rate constant of 19.16 × 10−3 min−1 and reduced the Chemical Oxygen Demand (COD) value of wastewater from 100.56 to 58.01 mg/L, potentially due to a synergistic combination of α-Fe 2 O 3 and ZnFe 2 O 4. This study underscores the promising potential of transition metal-doped iron-silicate glasses as potent photocatalysts for wastewater treatment. [ABSTRACT FROM AUTHOR]

With the rapid development of wireless charging technology, there is a growing demand for ferrite materials with high permeability, high saturation magnetic induction intensity, and low power loss. This study aims to enhance the electromagnetic performance of NiCuZn ferrite by co-doping Nb5+ and Li+. The influence of the doping levels Nb5+ and Li + on the morphology, crystal structure, and electromagnetic properties of NiCuZn ferrite were studied in detail. Structural analysis shows that the lattice constant decreases as the Nb5+-Li+ doping concentration increases, and the NiCuZn ferrite exhibits a high density and homogeneous microscopic morphology at the optimum concentration of x = 0.004. Specifically, at a doping concentration of x = 0.004, the magnetic permeability at 1 MHz measured at 1112.1, the saturation magnetic induction intensity reached 458.98 mT, and the power loss was minimized to 521.85 kW/m3, demonstrating significant improvement in the transmission power of wireless charging applications. [ABSTRACT FROM AUTHOR]

Significant phase transformations occur in the ultralow‐carbon 11.3Cr–1.7Mn–0.8Ni steel during heat treatment processes, producing distinct microstructures. Herein, optical microscopy, electron backscattered diffraction, electron probe microanalysis, and transmission electron microscopy techniques are employed to investigate the structural transformation of the steel after heat treatment at temperatures ranging from 730 to 1000 °C. The results reveal that the steel's microstructure gradually transforms from predominantly ferrite phase with minor martensite to mainly martensite with a small amount of ferrite structure, ultimately reaching almost complete martensite structure with a uniform distribution of low levels of retained δ‐ferrite strip at all tested temperatures. The band contrast curve exhibits unimodal characteristics in a single‐phase structure and bimodal characteristics in a biphase structure; the rise in the average kernel average misorientation value corresponds to higher degrees of misorientation and the formation more martensite; a grain orientation spread threshold of 4° could be utilized for qualitative determination regarding whether complete austenitic transformation occurs or not. Furthermore, the segregation of Cr, Mn, and Ni elements in hot‐rolled samples constitutes an intrinsic factor leading to microstructural alterations. Finally, hot‐rolled martensite exhibits a cellular structure, whereas heat‐treated martensite displays a lath bundle structure; both possess a body‐centered‐cubic crystal structure. [ABSTRACT FROM AUTHOR]

We embedded cobalt ferrite (CoFe 2 O 4 , CFO) nanoparticles on carbon nanotubes (CNTs) through oxidation and wet chemical methods to prepare CNT@CFO. Subsequently, aramid nanofiber (ANF)-reinforced aerogel films CNT@CFO/ANF were prepared by vacuum-assisted filtration and freeze-drying. CNT@CFO is evenly interspersed in the ordered ANF layers, giving the aerogel film excellent flexibility and stretchability. In electromagnetic interference shielding (EMI SE) applications, electromagnetic coupling and rich heterogeneous interfaces alleviate impedance mismatch and improve the attenuation of electromagnetic waves. The CNT@CFO/ANF film with a thickness of 30 μm exhibits an EMI SE value of 35 dB in the X-band. The absorption coefficient of CNT@CFO/ANF exceeds 0.9, which effectively reduces secondary reflection pollution compared with CNT/ANF. In photothermal conversion applications, the dual light absorption of conjugated CNTs and semiconductor CFO enables the composite film to exhibit rapid and stable photothermal heating. At AM 1.5G intensity, the stable temperature of CNT@CFO/ANF is 60.1 °C, which is higher than that of CNT/ANF. In addition, the CNT conductive network enables films to achieve rapid response, adjustable, and long-term stable joule heating capabilities. These results indicate that CNT@CFO/ANF aerogel films prepared by a simple and efficient method have great application potential in the field of multifunctional flexible devices. [Display omitted] [ABSTRACT FROM AUTHOR]