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One of the main challenges in operating multistate manufacturing systems (MMSs) is maintaining stable and robust production against various disruptions. Therefore, an urgent need exists for an operation and maintenance (O&M) method that optimises MMS resilience, i.e. the capability of withstanding or recover from disruptions of various sources. Consequently, this study proposes an integrated resilience-oriented production and maintenance scheduling approach for MMSs. This approach enhances MMS resilience by reinforcing its adaptivity to the variation in production requirements. Based on a conceptual investigation of operational uncertainty and its mechanism of disruption, this study devotes to (i) formulating a performance loss-based resilience measurement with consideration of operational uncertainties and (ii) proposing a reinforcement learning-based approach to schedule MMS operation and maintenance activities for MMS components of different performance states. An industrial case study of a ferrite phase shifter manufacturing system is subsequently conducted to validate the proposed approach. Results demonstrate the effectiveness of the proposed approach in the resilience optimisation of MMSs. [ABSTRACT FROM AUTHOR]

This study investigates the effects of Zn substitution on the magnetic properties of ∼5 nm cobalt ferrite nanoparticles (ZnxCo1−xFe2O4, where x = 0, 0.13, 0.34, and 0.55), demonstrating that Zn substitution induces complex changes in spin canting and prompts a redistribution of cations among the sublattices. We reconstructed the magnetic structure of these spinel ferrites by integrating the classical two-sublattice Néel model of ferrimagnetism with the data obtained from 57Fe Mössbauer spectrometry. Consequently, this research provides a comprehensive understanding of how Zn substitution tunes the magnetic properties of CoFe2O4 nanoparticles, offering valuable insights into the development of magnetic materials with tailored properties for various applications. [ABSTRACT FROM AUTHOR]

Mass transport in bulk spinel ferrites NiFe2O4 is studied computationally using the kinetic activation–relaxation technique (k-ART), an off-lattice kinetic Monte Carlo algorithm. Diffusion mechanisms—difficult to observe with molecular dynamics—are described by k-ART. Point defects are assumed to be responsible for ionic diffusion; thus, both cation and anion defects are investigated. This work focuses on vacancies and interstitials by comparing their properties with two Buckingham potential parameterizations: one with nominal charges and the other with partial charges. Both potentials are corrected at short distances, thus allowing interstitial diffusion and avoiding the catastrophic infinite energies appearing with Buckingham at short distances. The energy landscape along different pathways is described in detail. Both potentials predict the same mechanisms but different migration energies. Mechanisms by which a normal spinel is transformed to an inverse spinel via cation diffusion are unveiled, and diffusion coefficients are predicted. We find that interstitial Ni diffusion involves the movement of two Ni ions and that O interstitials trigger a collective diffusion of O ions, while an O vacancy diffuses by an O ion moving to the center of a cuboctahedron. [ABSTRACT FROM AUTHOR]

The mixed zinc-ferrite spinel magnetic nanoparticles (MNPs) with the general formula ZnxFe3−xO4 are among the most extensively studied families of Fe oxides due to their interesting and diverse chemical, electronic, and magnetic properties. These systems offer the possibility of surface functionalization and possess high biocompatibility, making them highly attractive for applications in biomedicine, such as magnetic fluid hyperthermia (MFH). The efficiency of the MFH process relies on the magnetic, structural and morphological properties of the MNPs. The substitution with the Zn ion and the cationic distribution, as well as the synthesis process employed, have a direct impact on the final properties of these oxides. Therefore, it is essential to have tools that enable a comprehensive characterization of the system to assess its performance in MFH. In this study, we have synthesized four ZnxFe3−xO4 MNP systems using three different methods: two by thermal decomposition at high temperatures, one by co-precipitation, and another by co-precipitation followed by ball milling. We analyze the effect of these various synthesis processes on the magnetic and crystallographic properties, aiming to correlate them with the response of each system in MFH. Neutron diffraction data are employed to determine the cation site occupation and to investigate the correlation with the synthesis method. MFH measurements were conducted in media of diverse viscosities, revealing different values of specific loss power, thus demonstrating a clear dependence on the synthesis process and Zn content. [ABSTRACT FROM AUTHOR]

In this paper, the effects of hydrostatic stress on the magnetic properties of Mn-Zn power ferrites are discussed. Ring cores were embedded in cement and the curing process gradually exerted pressure on the core. A novel testing method was developed to continuously measure the power losses and the magnetic susceptibility in dependence on magnetic excitation at a fixed frequency and room temperature with a vector network analyzer. After 450 h, a maximum compressive stress of 120 MPa was reached. Power loss up to 300% was observed, while magnetic susceptibility dropped by 35%. The magneto-mechanical effect on core losses was simulated with the Hodgdon–Esguerra hysteresis model, showing excellent agreement with tested results, which allows us to predict the behavior of ferrite tiles embedded in load-bearing surfaces for wireless power transfer (WPT) applications. [ABSTRACT FROM AUTHOR]

The complex permeability and power losses are very important parameters for soft magnetic materials. In this paper, the temperature dependence of these two parameters is investigated for Mn–Zn ferrite. The Hopkinson peak was observed at 440 K below the Curie temperature (TC), and the domain-wall resonance peaks and the natural resonance peaks gradually move to lower frequencies until the Hopkinson temperature (TH). Further, the domain-wall resonance peaks from relaxation type to resonance type are observed by fitting the permeability spectrum, which is related to the reduction of the loss factor. In addition, the power losses were measured from 245 to 365 K and divided into hysteresis loss (Ph), eddy current loss (Pe), and excess loss (Pexc). Each loss contribution was discussed to be dependent on temperature. The results show that at high temperatures and high frequencies, the thermal superposition effect will cause an abnormal increase in excess loss. [ABSTRACT FROM AUTHOR]

The solid-state synthesized dense ceramic composite, consisting of M-type hexaferrite Ba 0.5 Sr 0.5 Fe 12 O 19 and inverse spinel ferrite Ni 0.3 Co 0.2 Zn 0.5 Fe 2 O 4 (NCZFO) with varying concentrations, demonstrates the presence of apparent colossal permittivity along with dielectric relaxation behaviors at the higher frequency regions for all the composites. This phenomenon manifests as a giant dielectric permittivity of approximately 10 5 at 1 kHz, gradually decreasing to around 10 3 at 1 MHz at room temperature. It can be attributed to the Maxwell–Wagner interfacial polarization, which arises from the presence of different conductivity regions within the microstructures of the composite. The dielectric permittivity and the activation energy are also increased with higher NCZFO content, indicating an intricate microstructure influencing the electrical response by impacting charge carrier movement and ion migration. The presence of both Fe and Co cation defects and oxygen vacancies enhanced non-uniformity in the microstructure with different conductivity regions. The appearance of relaxation peaks in the higher frequency region can be attributed to inhomogeneity in the microstructure. In conjunction with the equivalent circuit analysis, the Nyquist plot confirmed that the electrical response at a lower frequency primarily arises from grain boundaries. The departure from ideal Debye-type relaxation behavior in the electrical response is also confirmed by impedance analysis. Furthermore, the step-like increase in AC conductivity with frequency suggests that the electrical response observed at a lower frequency is not intrinsic. Rather, it indicates the depletion of insulating grain boundaries due to diffusive ion motions resulting from defects. This observation reinforces that the high dielectric permittivity observed in the composite is not an inherent characteristic of the constituent materials. Instead, it arises from the microstructure and the influence of defects within the material. [ABSTRACT FROM AUTHOR]

The cellulose fibers that form washi are longer than those of regular paper made from wood pulp. Hence, the mechanical properties of washi can be higher than those of conventional paper. This study evaluated the magnetic, magnetostrictive, and tensile properties of negative magnetostrictive cobalt ferrite (CoFe2O4) particle dispersed handmade washi (washi−CoFe2O4). The CoFe2O4 additives magnetized the washi, which displayed negative magnetostriction with the fiber direction perpendicular to the magnetic field and in the parallel fiber direction. Concerning the mechanical properties, the washi−CoFe2O4 displayed an elongation of up to 77% after yielding. [ABSTRACT FROM AUTHOR]

In the present work, magnetic nickel ferrite (NiFe2O4) have been synthesised using low temperature combustion method and then modified with Cetyltrimethylammonium bromide (CTAB) to form a magnetic composite. Prepared composite (CTAB-NiFe2O4) was used as an adsorbent for removing brilliant green dye from aqueous solution. Adsorbent was investigated by using various techniques like Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy, energy-dispersive spectra, thermogravimetric analysis and pH of point zero charge. Different parameters such as effect of contact time, pH, adsorbent dose and initial dye concentration were studied for the adsorption of dye. The optimum values observed were 170 minutes equilibrium time at pH 6 and adsorbent dose 0.6 g. Various adsorption kinetic models such as pseudo first-order kinetic model, pseudo second-order kinetic model and Elovich model were used to determine the nature of adsorption. Pseudo second-order kinetic model fitted better with higher R2 value which indicated that the adsorption was chemical in nature. Langmuir isotherm was best fitted to experimental data for the adsorption of brilliant green dye with maximum adsorption capacity 'Qe' 250 mg/g. It revealed that the adsorption in this study takes place on homogenous surface and follows monolayer pattern. Therefore, for the removal of Brilliant green dye from wastewater using composite (CTAB-NiFe2O4) can be considered as an effective adsorbent. [ABSTRACT FROM AUTHOR]

The detection of defects can be seriously affected by lift-off and tilt effects, which represents significant challenges for eddy current testing (ECT). In this paper, an innovative eddy current sensor with E-core ferrite is proposed to overcome these challenges. The sensor comprises two excitation coils, one receiving coil, and an E-shaped ferrite core. The excitation coils and receiving coil are wound on two sides and the middle of the E-core, respectively. Specially, the two excitation coils are wound in opposite directions, resulting in magnetic field cancellation in the middle receiving coil when there is no defect in the plate. All the design principle, simulation, and experimental verification demonstrate the feasibility and excellent performance of the proposed sensor. Moreover, the proposed sensor can assess the depth of defects and achieve defect localisation based on the proposed measurement method. The results indicate that the defect depth can be accurately classified and identified based on the measured signal amplitude. The localisation of defects on aluminium sheets shows excellent results for depths ranging from 0.6 mm to 2.0 mm. However, for stainless-steel sheets, the defect localisation results show an unexpected error rate of over 15% when the defect depth is less than 1.1 mm. [ABSTRACT FROM AUTHOR]

Multi-dimensional wireless power transmission is a critical element in the development of capsule robots. To solve the problem caused by the increasing number of functions of new capsule robots and the fact that the traditional three-dimensional receiving coil occupies excessive inner space, a two-dimensional square transmitting coil with an embedded ferrite core is proposed. The proposed transmitting coil consists of two pairs of rectangular solenoid coils distributed radially along the human body. By changing the direction of the current flow, it can generate a two-dimensional magnetic field covering the whole central plane. This paper presents a theoretical model and conducts finite element simulations to analyze the magnetic flux density in the center plane. To evaluate the effectiveness of the proposed system, two prototypes of transmitting coils with and without ferrite cores are created, tested and compared to assess the performance improvements. Results indicate that the transmitting coil with a ferrite core increases the power transfer efficiency from 5.07% to 6.11%. In addition, attitude experiments reveal that the receiving coil efficiently captures sufficient energy at various angles when operated in the center plane. [ABSTRACT FROM AUTHOR]

Nanocomposites of SrBi (2-X) (CF) X Nb 2 O 9 (SBNCF) (CF=CoFe 2 O 4 for X = 0.0 to 0.5 with a step increment of 0.1) were synthesized using the hydrothermal method and characterized for their structural, morphological, elastic, and optical properties. The incorporation of CF into SrBi 2 Nb 2 O 9 (SBN) resulted in hybrid composites with tailored properties. X-ray Diffraction (XRD) with Rietveld refinement analysis confirmed the formation of orthorhombic SBN and spinel CF phases. Field Emission Gun Scanning Electron Microscopy (FEG-SEM) revealed that SBN exhibits a plate-like morphology, with the incorporation of CF into the SBN matrix resulting in both plate-like and octahedral-shaped grains. The Brunauer–Emmett–Teller (BET) method was used to determine the pore radius and surface area, both of which were found to have increased, indicating an enhancement in photocatalytic performance. The presence of the constituent elements in the prepared compositions was confirmed by Energy Dispersive Spectroscopy (EDS). Fourier Transform Infrared Spectroscopy (FTIR) spectra were used to determine elastic properties, suggesting potential applications in electronic noise filtering. From Diffuse Reflectance Spectroscopy (DRS), a recognizable semiconducting behavior and band gap bowing were noticed in SBNCF nanocomposites on the obtained energy band gap values (2.20 eV–1.56 eV) compared to the SBN host matrix (3.16 eV). The materials exhibited strong emission peaks at 470 nm, 528 nm, 584 nm, and 703 nm upon the excitation of 425 nm light using Photoluminescence (PL) spectroscopy. The white emission was predominant at room temperature in all the produced samples and the corresponding color temperature values range from 5865.93 K to 7599.05 K from the CIE diagram. The SBNCF materials are promising candidates in photocatalytic reactions and white light-emitting diodes (w-LEDs) based on their enhanced optical properties. [ABSTRACT FROM AUTHOR]

A method to track in situ static recrystallization, key to control the mechanical performance in steels, was developed. It relies on monochromatic X-ray diffraction experiments. The validity is discussed by comparison with post-mortem methods (EBSD and hardness). The beginning of recrystallization is easily detected thanks to the precision and time resolution of our method. In addition, our method can easily be coupled with other in situ techniques to investigate phase transformation or recovery. [ABSTRACT FROM AUTHOR]

Martensite and bainite are formed from austenite through the rapid application of Bain's strain. In several studies, martensite is considered as a body-centered tetragonal phase, but it can also be viewed as bcc ferrite supersaturated with carbon, subject to internal residual stresses from incomplete relaxation of Bain's strain. Recent electron backscatter diffraction measurements have revealed a broad spectrum of tetragonality in quenched martensite, which can be attributed to the diversity of internal stress rather than variations in carbon distribution. Therefore, a thermodynamic unit cell model is developed to calculate the kinetics of carbon atom occupancy in particular kinds of octahedral interstitial lattice sites, contributing to tetragonality in loaded ferrite. The model includes a Zener-ordering term that influences carbon atom distribution and consequently affects tetragonality. Simulations suggest that carbon redistribution among octahedral interstitial lattice sites reaches equilibrium with internal stress within an hour at room temperature. The presented model provides a framework for understanding tetragonality in martensite and bainite, incorporating the effects of internal stress and carbon atom distribution in particular kinds of octahedral interstitial lattice sites. [ABSTRACT FROM AUTHOR]

The chemical solution-deposited zinc ferrite (ZFO; ZnFe2O4) RRAM devices on Pt/Ti/SiO2/Si substrate are being reported. Fabricated devices show the positive as well as negative unipolar switching memory properties. Thickness of ZFO thin films in Au/ZFO/Pt structure was varied to explore the resistive switching behavior. It is reported that forming voltage and resistance of the device increase by increasing the number of ZFO layers. Our results reveal that ZFO thin film deposited by eight times spin coating with a thickness of eight layers illustrates stable resistive switching with the most steady Set (2 V) and Reset voltages (0.5 V) as compared to the devices with two, four, and six layers. It also demonstrates the enhanced endurance of greater than 300 switching cycles and stable time-dependent resistance greater than 104 s. The current transport mechanism is Ohmic at low-resistance state, while it leads to Schottky emission at high-resistance state. The possible switching mechanism is also discussed for the possible application of ZFO-based memory for nonvolatile RRAM devices. [ABSTRACT FROM AUTHOR]

The chemical solution-deposited zinc ferrite (ZFO; ZnFe2O4) RRAM devices on Pt/Ti/SiO2/Si substrate are being reported. Fabricated devices show the positive as well as negative unipolar switching memory properties. Thickness of ZFO thin films in Au/ZFO/Pt structure was varied to explore the resistive switching behavior. It is reported that forming voltage and resistance of the device increase by increasing the number of ZFO layers. Our results reveal that ZFO thin film deposited by eight times spin coating with a thickness of eight layers illustrates stable resistive switching with the most steady Set (2 V) and Reset voltages (0.5 V) as compared to the devices with two, four, and six layers. It also demonstrates the enhanced endurance of greater than 300 switching cycles and stable time-dependent resistance greater than 104 s. The current transport mechanism is Ohmic at low-resistance state, while it leads to Schottky emission at high-resistance state. The possible switching mechanism is also discussed for the possible application of ZFO-based memory for nonvolatile RRAM devices. [ABSTRACT FROM AUTHOR]

Traditional soft ferrite manufacturing is limited to simple geometries and materials, while 3D printing offers greater flexibility for complex designs. Notably, soft ferrites are crucial for magnetic couplers (pads) in inductive power transfer (IPT) systems to achieve efficient wireless power transmission. The adoption of soft ferrite 3D printing in IPT systems could lead to significantly improved magnetic coupler design, yet research in this area is limited. Hence, the paper first makes a comprehensive comparison of the existing soft ferrite 3D printing methods to ascertain their suitability for magnetic couplers in IPT systems, and then proposes the binder jetting (BJT) as a potential 3D printing approach that could be appropriate for IPT magnetic coupler implementation being versatile, cost‐effective, and suitable for large‐scale manufacturing with high precision. This paper explores the suitability of BJT by 3D printing toroid cores with Mn–Zn ferrite powder under different sintering temperature profiles. Experimental results are presented to show that toroid cores can be 3D printed with high printing precision, mechanical strength, and a relative permeability of 10. This paper also highlights the impact of sintering temperature on 3D‐printed cores, the challenges, limitations, and future research directions of soft ferrite 3D printing for IPT magnetic couplers by the BJT method. [ABSTRACT FROM AUTHOR]

BaFeO 3 -based perovskites have recently attracted considerable attention as a highly promising matrix for the development of robust and electrochemically active electrodes for solid oxide electrochemical cells based on both oxygen-ionic and proton-conducting electrolytes. The excellent redox activity and mixed ionic‒electronic conducting behavior of BaFeO 3 -based materials support their application not only as oxygen electrodes but also as fuel electrodes. In the present study, Pr 0.6 Ba 0.4 FeO 3–δ is employed as the initial composition, which is then subjected to various Ni-doping strategies until the formation of stoichiometric (Pr 0.6 Ba 0.4 Fe 0.9 Ni 0.1 O 3–δ) and non-stoichiometric (Pr 0.6 Ba 0.4 FeNi 0.1 O 3–δ) compounds. The crystal structure, phase relationships, conductivity, and electrochemical activity of these materials have been comprehensively studied in both oxidizing and reducing atmospheres in an effort to identify the best doped derivatives. The experimental results demonstrate that Ni doping represents a promising approach to increase the electrochemical activity of the origin electrode, as evidenced by the observed improvement in electrical conductivity in oxidizing atmospheres and the formation of electrocatalytically active exsolved particles in reducing atmospheres. At the same time, the stoichiometric composition results in superior electrode performance relative to the non-stoichiometric composition, indicating that conventional co-doping of ABO 3 perovskites may prove more advantageous than B-excess (or A-deficient) analogs. Therefore, this work elucidates the intricate composition–structure–property relationships of barium ferrite materials fort their further high-temperature electrochemical applications. [Display omitted] • Various Ni-doping methods of Pr 0.6 Ba 0.4 FeO 3–δ (PBF) was used. • Pr 0.6 Ba 0.4 Fe 0.9 Ni 0.1 O 3–δ and Pr 0.6 Ba 0.4 FeNi 0.1 O 3–δ were prepared and studied. • Their characterizations were provided in both oxidizing and reduced atmospheres. • Ni-doped materials exhibited improved electrical and electrochemical properties. • The best electrode performance was achieved for Pr 0.6 Ba 0.4 Fe 0.9 Ni 0.1 O 3–δ. [ABSTRACT FROM AUTHOR]

This work describes the synthesis, characterization, and photocatalytic evaluation of a polypyrrole-reinforced zinc-nickel mixed metal ferrite (PPy@ Zn 0.5 Ni 0.5 Fe 2 O 4) nanohybrid. A facile hydrothermal process is employed to synthesize the nanostructured zinc-nickel mixed metal ferrite (ZNF), and in situ oxidative polymerization is utilized to create the PPy nanohybrid. In this nanohybrid, PPy plays multiple roles: preventing charge recombination, reducing photocorrosion, mitigating particle aggregation in ZNF, and enhancing charge transfer and visible light absorption. The combined electron-capturing ability, intrinsic conductivity, and extensive π-conjugation of PPy, along with the magnetic nature of ZNF, render the PPy@ZNF catalyst highly efficient. The results of photoluminescence, impedance, and UV/Vis analysis confirm that PPy plays a critical role in enhancing photocatalytic performance by facilitating charge transfer and extending visible-light absorption. In practical environmental applications, the PPy@ZNF nanohybrid demonstrated superior photocatalytic activity compared to ZNF alone, degrading 98.5 % of malachite green dye under W-lamp light within 80 min, with a rate constant of 0.031 min−1. Scavenger and cyclic experiments identified the active species involved in dye degradation and assessed the reusability of the nanohybrid. Extensive testing revealed the optimal conditions for photocatalytic efficiency; the considered variables included light intensity, catalyst dose, dye concentration, temperature, irradiation time, and pH. These findings suggest that the PPy-reinforced ZNF nanohybrid offers cost-effectiveness, magnetic recoverability, structural stability, and high efficacy as a visible light-driven catalyst, making it a promising candidate for diverse environmental remediation applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Due to the advancement of industrialization, water pollution has become an alarming global issue. Many organic dyes, such as crystal violet and rhodamine B, present in industrial wastewater are causing severe health problems. Both of these dyes are carcinogenic. For their degradation, ferrites are synthesized in this research. Ferrites have high absorbing potential in visible regions and fast movement of charge carrier species. Therefore, the ferrites are potentially used in photocatalysis to purify contaminated water. Graphitic carbon nitride shows enhanced separation of charges, which lowers the rate of recombination of charge carrier species. Lithium nickel ferrite, lithium nickel ferrite doped with terbium, and its composite with graphitic carbon nitride (g-C 3 N 4) are synthesized by sol-gel and ultra-sonication methods, respectively. The prepared samples are analyzed by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Scanning electron microscopy (SEM), Electrochemical impedance spectroscopy (EIS), and Mott-Schottky analysis. The bandgap of LiNiFe 2 O 4 and LiNiTbFe 2 O 4 was 2.35 eV, and 1.87 eV, respectively. LiNiTbFe 2 O 4 @g-C 3 N 4 degraded 86 % crystal violet and 83 % rhodamine B in 120 min. The LiNiTbFe 2 O 4 @g-C 3 N 4 composite showed the maximum degradation and can be potentially used in wastewater treatment. [ABSTRACT FROM AUTHOR]

Ferrite samples with enhanced magneto-dielectric properties are more essential in electromagnetic applications. Therefore, a parent composition of Fe 3 O 4 has been modified by substituting 3 d transition metal elements (Co, Ni, Mn) at a single Fe atom using the co-precipitation synthesis method. The structural properties of the synthesized Fe 3 O 4 , NiFe 2 O 4 , CoFe 2 O 4 , and MnFe 2 O 4 samples have been evaluated from the X-ray diffraction patterns. The surface morphology and microstructures of the studied samples were studied by field emission scanning electron microscopy and the average grain size of all the studied samples varied from 60.11 to 106.03 nm. The magneto-dielectric properties were analyzed by frequency dependent permeability (μ) and permittivity (ε) measurements for the range of 100 Hz to 100 MHz. The conduction process for the synthesized ferrites has been noticed from the ac conductivity (σ ac). The localized relaxation mechanism for the studied ferrites has been observed from the variation of imaginary portion of the electric modulus (M") and the impedance (Z"). Moreover, the mismatch (Z/η ο) between the impedance of the antenna substrates (Z) made of the studied samples and air (η ο) has been evaluated from the permeability and permittivity. Finally, NiFe 2 O 4 has been derived as a suitable ferrite for miniaturizing devices over a frequency range of 10 kHz-6.5 MHz. [ABSTRACT FROM AUTHOR]

Gadolinium-substituted cobalt manganese ferrite nanoparticles with the composition Co 0.6 Mn 0.4 Gd x Fe 2- x O 4 (where x ranges from 0.0 to 0.08, with x = 0.02) were prepared through the sonochemical method. X-ray diffraction reveals that grown samples are single-phase cubic spinel belonging to space group Fd 3 m, where the crystallite sizes decrease with increasing Gd3+ content. At high doping ratios (x > 0.06), there was a slight increase in crystallite size compared to that of pure Co–Mn ferrite (x = 0), while the lattice parameter (a) decreased in the low doping range of Gd (x < 0.06), resulting in a reduction in crystallite size. Bertaut's method confirms that 80 % of the tetrahedral (A) sites were occupied by Mn ions, while the remaining sites were occupied by other cations in the octahedral (B) positions. Gd3+ ions were found exclusively in the octahedral-B sites. Co2+ ions were expected to occupy the octahedral-B site, which was confirmed in this study for the x = 0.0 and 0.02 samples. Field emission scanning electron microscopy shows the samples are agglomerated and have dense structures. Fourier transform infrared and Raman spectra validated the presence of spinel ferrite modes. Dielectric investigations indicate that as the Gd3+ content exceeds x = 0.0, the dielectric constant and dielectric loss decrease at lower frequencies. The observed dielectric behavior exhibited typical dispersion patterns attributed to Maxwell-Wagner polarization. Furthermore, changes in dielectric properties were observed as the Gd3+ content in Co 0.6 Mn 0.4 Gd x Fe 2- x O 4 nanoparticles increased, which can be attributed to the presence of oxygen vacancies and variations in the distribution of Fe3+ ions at both A and B-sites. [ABSTRACT FROM AUTHOR]

In order to improve the microwave-absorption performance of barium ferrite and broaden its microwave-absorption band, BaFe12O19, Ba0.95Ca0.05Fe12O19, and Ba0.95Ca0.05Fe12−xCoxO19 (x = 0.1, 0.2, 0.3 and 0.4, respectively) hexaferrites were synthesized by the solid-state reaction method, and the influence of Co ion substitution on the phase composition, microstructure, magnetic properties, and microwave-absorption ability of the ferrites in this system was studied. Introducing minor Co ions (x < 0.2) facilitated sintering and grain growth. At x ≥ 0.2, XRD revealed the emergence of the Co2X phase alongside the BaM phase. Increasing Co ion concentration and the secondary X-phase led to slight reductions in saturation magnetization (69 to 63.5 emu/g) and substantial decline in coercivity (2107.02 to 111.21 Oe), attributed to grain size growth and Co2X's soft magnetic nature. Notably, Co2X incorporation significantly enhanced the microwave absorption and provided a tunable absorption band from the Ku to the C band. For a sample with a thickness of 2.0 mm and a doping level of x = 0.2, a minimum reflection loss of −59.5 dB was achieved at 8.92 GHz, with an effective absorption bandwidth of 3.31 GHz (7.07–10.38 GHz). The simple preparation method and good performance make Ba0.95Ca0.05Fe12−xCoxO19 (x = 0.1, 0.2, 0.3 and 0.4, respectively) hexaferrites promising microwave-absorbing materials. [ABSTRACT FROM AUTHOR]

In this study, metal-doped quaternary nano ferrites (Co0.5Zn0.25M0.25Fe2O4, M = Ba, Cu, Mn, Ni and Sr) were synthesized and evaluated for their efficiency in removing Direct Orange-108 Acid Dye from aqueous solutions. The adsorption performance of these materials was systematically investigated under various conditions. Optimal pH levels for dye removal were found to be pH 2 (41.45 mg/g), pH 2 (36.37 mg/g mg/g), pH 4 (31.13 mg/g), pH 4 (44.75 mg/g), and pH and 3 (39.62 mg/g) at optimal dosage of 0.05 g/50 mL and at an initial concentration of at 75 ppm and 50 ppm for Co0.5Zn0.25Ba0.25Fe2O4, Co0.5Zn0.25Cu0.25Fe2O4, Co0.5Zn0.25Mn0.25Fe2O4, Co0.5Zn0.25Ni0.25Fe2O4 and Co0.5Zn0.25Sr0.25Fe2O4 respectively. Additionally, the study revealed that an optimum temperature of 40 °C enhanced the adsorption efficiency, resulting in adsorption capacities of 41.92 mg/g, 40.56 mg/g, 33.22 mg/g, 48.00 mg/g, and 43.71 mg/g for Co0.5Zn0.25Ba0.25Fe2O4, Co0.5Zn0.25Cu0.25Fe2O4, Co0.5Zn0.25Mn0.25Fe2O4, Co0.5Zn0.25Ni0.25Fe2O4 and Co0.5Zn0.25Sr0.25Fe2O4 respectively. The shaking time with optimal results were obtained at 45 and 60 min. Similarly, as a photocatalyst have optimal pH at 2, 3 and 4, optimum dose 0.05 g/50 mL, initial concentration of dye was 50 and 75 ppm with contact time of 45 and 60 minutes at 40 °C as optimum temperature. The pseudo second order adsorption kinetic model and Langmuir adsorption equilibrium isotherm displayed strong fitting for experimental data. While degradation kinetic follow BMG and second kinetic model. NH4OH solution showed maximum desorption The thermodynamic study demonstrated the exothermic character. The adsorption study of real textile effluents was also conducted that yielded valuable information. Highlights: Novel metal doped quaternary nano ferrites Co0.5Zn0.25M0.25Fe2O4 (M = Ba, Cu, Mn, Ni and Sr) were synthesized, characterized, and used for dye adsorption. Langmuir adsorption isotherm and pseudo second order kinetic model fitted best and proved most appropriate for this study. The size, changeable properties and shape are the most notable characteristics of nano ferrites, therefore the use of ferrites in many applications is enhancing day by day. [ABSTRACT FROM AUTHOR]

We report the infrared absorption properties of polyaniline nanocomposites (AgFe2O3/ZnO) with different amounts of PANI (5 and 10 wt%) powder samples by in situ chemical oxidation polymerization synthesis. In contrast, silver ferrite nanomaterial has been synthesized using a hydrothermal approach. X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) were used to characterize the prepared samples. Rhombohedral structures were seen in the pure (AgFe2O3/ZnO) and its PANI composites. The size of the crystallites was found between 30 to 40 nm. The SEM images of the composites confirmed the morphology of prepared samples. The FTIR spectrum for each of the samples consists of two wide absorption bands that correspond to the tetrahedral V1 and octahedral V2 sites bending vibrations. Force constants were found higher for tetrahedral sites as compared to octahedral sites. FTIR parameters have been used to calculate the Bulk modulus (B), Rigidity modulus (R), Young's modulus (Y), and Poisson ratio (σ). Elastic parameters for PANI doped ferrites have improved significantly compared to pure AgFe2O3/ZnO ferrite due to strong inter atomic bonding. This can be beneficial in overcoming physical stresses that may arise during material fabrication and commercialization. Debye temperature increased with increasing PANI concentration. [ABSTRACT FROM AUTHOR]

Various techniques, such as optical microscopy, high‐temperature confocal laser scanning microscopy, scanning electron microscopy, electron backscatter diffraction, and thermodynamic calculations, are employed to analyze the optimization mechanism of Ce on the inclusions and microstructures in F38MnVS as‐cast samples. The results show that the addition of Ce inhibits MnS precipitation at the grain boundaries and significantly reduces the diameters and aspect ratios of the inclusions. After Ce treatment, a new type of composite inclusion appears in the steel. The modification of the inclusions by Ce promotes the optimization of the as‐cast microstructure during solidification, which mainly exhibits austenite grain refinement and polygonal ferrite formation in the grains. Based on the misfit degree theory, the refinement of the austenite grains is because of the nucleation of austenite grains facilitated by Ce2O2S and CeAlO3. The increased nucleation of the intragranular polygonal ferrite is mainly attributed to Ce2O2S, Ce2S3, CeAlO3, and VC, which can promote the nucleation of α‐Fe. Simultaneously, the addition of Ce reduces the phase transition temperature, increases the driving force of the phase transition, and increases the nucleation rate. This study's results can provide a reference for the application of Ce treatment in the preparation of nonquenched tempered steel for automobiles. [ABSTRACT FROM AUTHOR]

This study reports new observations from the fabrication of high-aspect-ratio hollow tubes of SS410 through wire-arc directed energy deposition (wire-arc DED) process. Characterisation work was performed on a single tube as a function of its build height. The maximum ultimate tensile strength (UTS) of 1372 MPa and maximum yield strength (YS) of 980 MPa were achieved in the middle region of the tube. The highest UTS in the middle was attributed to the low delta ferrite content. The reduction of delta ferrite was found to be linked with the repetitive heating and cooling. In contrast, the top and bottom sections exhibit a substantial presence of delta ferrite, indicating that the cyclic effects were not considerable. Nevertheless, the presence of significant ductility in the bottom region of the component indicated the occurrence of tempering effects. This observation is further supported by the lower levels of local strain observed using KAM mapping. Overall, this work proposes a novel fabrication method for producing hollow sections with superior strength and ductile properties. [ABSTRACT FROM AUTHOR]

MnZn ferrite powders were prepared, based on the novel nano-in-situ composite method and through chemical sol–spray–calcination technology. Different dosage of CTAB were used, and the influences on the precursor sol solutions and precursor powders were studied. Also, the selected precursor powders (P-0.1CTAB) were calcined at 1060 °C in air for 3 h, and the sample (S-0.1CTAB) was considered to further exploration. The results indicated that the precursor sol and precursor powders were in their optimal state when adding 0.1 wt.% CTAB. Under this condition, the Zeta potential of the sol was 10.7 mV, and the colloidal particle size was 91.63 nm. The corresponding precursor powders can still maintain a nanoscale fine particle composition and be well dispersed. The S-0.1CTAB sample with hollow spherical shell composed of small particles of several hundred nanometers had pure MnZn ferrite phase, and the maximum value of saturation magnetization (Ms) was 53.46 emu/g. Moreover, there are three stages of the formation of MnZn ferrite during the CTAB-assisted synthesis process which are CTAB ionization and (Mn, Zn, Fe)(OH)(NO3)(H2O) formation stage, CTA + adsorption and colloidal particle formation stage, and (Mn, Zn, Fe)(OH)(NO3)(H2O) decomposition stage. [ABSTRACT FROM AUTHOR]

To fulfill the urgent demand for materials suitable for contemporary high-frequency applications, Eu-substituted Ni 0.55 Zn 0.35 Co 0.1 Eu x Fe 2- x O 4 (NZCEF, 0 ≤ x ≤ 0.10) composite ferrites were successfully synthesized by a solid-state reaction method, demonstrating characteristics apt for high-frequency functionalities. Detailed examination via SEM and EDS confirmed the compositional purity of these ferrites. Microstructural analysis indicates that the incorporation of europium results in a reduction of the average grain size in NZCEF composites, enhancing the material's densification. Measurements of resistivity and dielectric properties reveal that Eu doping affects the concentration of Fe2+ and Fe3+ ions as well as lattice defects within the ferrite, thereby leading to higher dielectric constants and resistivity (ρ , 6.51 × 108 Ω m). Magnetic analysis confirms that the substitution with Eu ions significantly increases both the coercivity and the ferromagnetic resonance frequency (f r), from 25.7 Oe and 445 MHz to 45.73 Oe and 1.22 GHz, respectively. This improvement is attributed to changes in grain size and domain wall motion. Consequently, Eu3+-substituted NZCEF ferrites exhibit superior electromagnetic properties, making them ideal candidates for advanced high-frequency material applications. [ABSTRACT FROM AUTHOR]

Removing radioactive corrosion products from Cr-containing iron oxides require a multi-step and multi-cycle decontamination process. The present article brings out the effect of divalent metal ion substitution on the release rate of chromium in the oxidative pre-treatment step. The non-stoichiometric cobalt chromium ferrites were synthesized, characterized and effect of Zn2+/Ni2+ substitution on the dissolution behavior was probed. The dissolution rates decreased with increasing the degree of inclusion and showed minima at ~ 0.4–0.6 atom% which is explained on the basis of lattice structure. It is concluded that the dissolution kinetics of native nickel–chromium ferrites in reactors increases with metal ion inclusion. [ABSTRACT FROM AUTHOR]

In this study, Cu-alloyed ductile cast iron treated by different first-step temperatures and times was investigated. The influence of the amount, morphology and distribution of acicular ferrite and retained austenite on the mechanical properties of the two-step austempered ductile iron (ADI) was analyzed. The results indicated that acicular ferrite was both nucleated and grown in two-step austempering. The thinner and sharper acicular ferrite formed at lower temperature at first step austempering was the ferrite needle, the thicker and blunt acicular ferrite formed at higher temperature at second step austempering was ferrite bunch. Ausferrite refinement, austenitic volume fraction and stability were strongly influenced by the phase transformation amount during first step austempering. A low transformation amount at the first- step of austempering process led to a decrease in austenite stability, which resulted in martensite formation and was detrimental to the mechanical properties. The overmuch transformation amount at the first-step of austempering process led to a similar morphologic ausferrite compared to single step ADI treated at the corresponding first-step temperature, which showed minimal improvement in the comprehensive mechanical properties. The maximum ultimate tensile strength, yield strength and elongation reached 1280, 1190 MPa, 10.2% respectively, as the first-step temperature increased to 280 °C due to the ausferrite refinement. The impact energy and fracture toughness maintained an increasing trend and reached a maximum at 93.5 J and 66.72 MPa m1/2, respectively, as the first-step temperature increased to 320 °C. The ultimate tensile strength and yield strength gradually increased with the first-step time increased, while the elongation, impact energy and fracture toughness gradually decreased. Ausferrite refinement was attributed to the appropriate amount of ferrite needles transformed at first step austempering, which was mainly reason for strength improvement. Austenitic volume fraction and stability increasing were the main influence factor for ductility and toughness of two-step Cu-alloyed ADI. The transformation-induced-plasticity (TRIP) effect was only effective as the induced transformation behavior was retarded to yield, which was also depended on austenitic stability. An optimal combination of ausferrite refinement, austenitic volume fraction and austenitic stability could be achieved through the appropriate first step transformation amount, which together influence the mechanical properties of Cu-alloyed ADI. [ABSTRACT FROM AUTHOR]

In this work, a novel Ba(CoTi)M-spinel magnetic composite with excellent microwave dielectric-magnetic properties has been developed through a hybrid ceramic process. It can be found that the spinel magnetic nanocrystals are uniformly dispersed at the Ba(CoTi)M grain boundary, while the formation of this particular micro-concrete structure has a good effect on ceramic densification and the reduction of magnetic-dielectric loss. The composite exhibits stable electromagnetic parameters in the S and C bands, as evidenced by a permittivity of about 8, a permeability value exceeding 2, and a relatively low magnitude of tanδ ε and tanδ µ on the order of 10−2. A magnetodielectric resonant antenna operating at 6.2 GHz with a −10 dB impedance bandwidth of 27.4%, and a low profile of 0.14λ 0 was designed, fabricated, and measured based on the hybrid ferrite. The hybrid ceramic scheme plays a crucial role in designing low-loss magnetic media, possessing significant application value in high-performance microwave antennas. • Ba(CoTi)M-spinel composite is prepared by a hybrid ceramic processing technique. • The dielectric-magnetic properties are effectively improved in S and C band. • The ferrite enables the miniaturization and wideband capabilities of MDRA. [ABSTRACT FROM AUTHOR]

The global water resource shortage has evolved into a pressing concern, necessitating the advancement of effective and environmentally sustainable water treatment techniques. Photocatalysis has surfaced as a hopeful technology for eliminating organic contaminants from wastewater because of its efficiency, cost-effectiveness, and eco-friendliness. Here, CeO 2 microspheres and Ni 0.5 Zn 0.5 Fe 2 O 4 (NiZn-ferrite) nanoparticles were synthesized using the hydrothermal method, followed by the fabrication of ternary hybrid composites CeO 2 /NiZn ferrite/multiwalled carbon nanotubes (MWCNT) via ultrasonic treatment. Various analytical techniques including XRD, FESEM, VSM, PL, BET and UV–Visible spectroscopy were employed to characterize the resulting synthesized samples. The hybrid ternary composites demonstrate remarkable efficiency in degradation of reactive red-35 dye through photocatalysis attributed to enhanced surface area. This efficiency is further enhanced when coupled with ultrasonic treatment, leading to a synergistic effect. The catalysts can be easily separated from the suspension due to their magnetic behaviour and thus hold great potential for utilizations in the field of wastewater treatment and environmental remediation. [ABSTRACT FROM AUTHOR]

LiZnTi ferrites with dense microstructure and excellent gyromagnetic properties are a critical class of materials for microwave ferrite devices. Many reported studies have demonstrated that grain refinement and good gyromagnetic properties is often contradictory. In this work, we have successfully prepared a highly-dense LiZnTi ferrite with small average grain size (<1.0μm) and good gyromagnetic properties by hot-pressure sintering (HPS) method. Interestingly, SEM images revealed that the hot-pressure sintering with zero holding time not only promoted densification of the LiZnTi ferrites, but also can realize their grain refinement, which effectively reduced porosity and improved gyromagnetic properties. Meanwhile, we found that the average grains size (GS ave.) of the HPS950 sample is smaller than the TS950 and HPS900 samples due to the synergistic effect of applied pressure (zero holding time) and Bi 2 O 3 liquid phase. Finally, a LiZnTi ferrite with uniform, dense grains (GS ave. = 0.85 μm and ρ r = 98.1 %) and good gyromagnetic properties (4π M s = 3859.6Gs and ΔH = 287.4 Oe) was obtained by hot-pressure sintering at ∼950 °C. [ABSTRACT FROM AUTHOR]

The non‐reciprocity of electromagnetic waves is a technology garnering significant attention for its applications in electromagnetic security and the mitigation of electromagnetic interference, serving to control radio waves in space. This article outlines a comprehensive design approach for a novel non‐reciprocal structure that integrates ferrite and metal patches. Additionally, it presents experimental results utilizing two types of ferrites. The experiments demonstrated the attainment of 15 dB isolation at both 6.25 GHz and 6.5 GHz. [ABSTRACT FROM AUTHOR]

MnZn ferrite powders were prepared based on the novel nano in situ composite method and through chemical sol-spray drying–calcination technology. The precursor powders were calcined at 1060 °C at different calcination times (1–9 h) to research the influences of the calcination time on MnZn ferrite powders. The research results revealed that all samples had similar morphologies composed of fine particles. The pure MnZn ferrite spinel phase can only be obtained when the calcination time does not exceed 3 h. Otherwise, some α-Fe2O3 or γ-Fe2O3 impurities will appear. The particle size descended with an increasing calcination time and then ascended. After 3 h of preservation, the smallest particle size was obtained, and it exhibited a unimodal distribution. The saturation magnetization (Ms) increased at first and decreased later with an increasing calcination time, and the optimal value (53.4 emu/g) was reached after holding for 3 h. In view of this work, the optimal calcination time is 3 h. [ABSTRACT FROM AUTHOR]

Abstract Traditional soft ferrite manufacturing is limited to simple geometries and materials, while 3D printing offers greater flexibility for complex designs. Notably, soft ferrites are crucial for magnetic couplers (pads) in inductive power transfer (IPT) systems to achieve efficient wireless power transmission. The adoption of soft ferrite 3D printing in IPT systems could lead to significantly improved magnetic coupler design, yet research in this area is limited. Hence, the paper first makes a comprehensive comparison of the existing soft ferrite 3D printing methods to ascertain their suitability for magnetic couplers in IPT systems, and then proposes the binder jetting (BJT) as a potential 3D printing approach that could be appropriate for IPT magnetic coupler implementation being versatile, cost‐effective, and suitable for large‐scale manufacturing with high precision. This paper explores the suitability of BJT by 3D printing toroid cores with Mn–Zn ferrite powder under different sintering temperature profiles. Experimental results are presented to show that toroid cores can be 3D printed with high printing precision, mechanical strength, and a relative permeability of 10. This paper also highlights the impact of sintering temperature on 3D‐printed cores, the challenges, limitations, and future research directions of soft ferrite 3D printing for IPT magnetic couplers by the BJT method.

A temperature factor is one of the main parameters in the synthesis of nanoparticles and can affect considerably the arrangement of atoms in the lattice. In the system of magnetically hard CoFe2O4 spinel ferrite, the distribution of cations directly determines the magnetic properties of the sample. It was studied, on products of co-precipitation synthesis followed by a temperature dependent sinterization, by x-ray diffraction (XRD), x-ray absorption (XAS) using synchrotron radiation, vibrating sample magnetometry, and 57Fe Mössbauer spectroscopy (MS). From the Rietveld refinement of XRD patterns, the site occupancies reveal the following trend: with a decrease in the sintering temperature, the inversion degree parameter γ, which is a fraction of Co ions residing in the octahedral sites, decreases. For the highest sintering temperature explored in this work, 1000 °C, γ ≈ 0.83 giving rise to (Co0.17Fe0.83)A[Co0.83Fe1.27]BO4 formulation. For the lowest sintering temperature explored, 500 °C, the inversion degree is approximately 0.69 giving rise to (Co0.31Fe0.69)A[Co0.69Fe1.31]BO4 formulation. The propensity for the cationic arrangement was also confirmed by MS. Qualitative analysis of XAS at Co L3,2 edges strongly supports the tendency observed by XRD: the lower the sintering temperature, the more Co ions tend to occupy the tetrahedral sites. The magnetic behavior of the samples is consistent with the particle size which was determined by transmission/scanning electron microscopies. The particle size is the product of different sintering temperatures after the primary synthesis. [ABSTRACT FROM AUTHOR]

Comparison of magnetoelectric properties of two-layer heterogeneous systems based on Mn0.4Zn0.6Fe2O4 ferrite and PbZr0.53Ti0.47O3 piezoelectric ceramics with ratio of the piezoelectric coefficient to the permittivity pd31/pɛ33 = 0.06 and two-layer heterogeneous systems based on Mn0.4Zn0.6Fe2O4 ferrite and PbZr0.53Ti0.47O3/epoxy piezoelectric composite with pd31/pɛ33 = 0.07 − 0.09 was carried out. It was revealed that the magnetoelectric properties of the heterogeneous systems enhance with an increase in pd31/pɛ33 for a piezoelectric. [ABSTRACT FROM AUTHOR]

Integration of compact, tunable, low-cost monolithic microwave integrated circuit-based bandpass filters on a semiconductor substrate has been a persistent requirement in the communication industry. In the present investigation, a compact reconfigurable bandpass filter is fabricated using a double T-transducer based on the phenomena of magnetostatic surface spin waves (MSSWs). The Ce-doped Bi0.1YIG 500 μm thick disks with cerium concentration in the range of 0.2–1.0 provide the path for the propagation of MSSWs. The operating frequency for this device extends from S to X band Rogers RT/duroid® substrate, which is used for planar microstrip filter design, fabrication, and testing for practical applications. The effect of the coupling gap between the two transducers was optimized using appropriate choice of lumped components to improve the performance of the filter. The best coupling was observed for 1.2 mm coupling gap. The simulated and experimental results confirm the lowest insertion loss of −1.24 dB. The operating frequency shows a large tunability of 132.3% with a relatively small bias field of 0.3–2.1 kOe. The promising characteristics of bandpass filters such as low passband insertion loss, narrow bandwidth, high bandpass reflection coefficient, and high band-stop rejection were achieved by varying the Ce concentration in YIG samples. [ABSTRACT FROM AUTHOR]

Improper ferroelectricity and canted ferromagnetism in antiferromagnetically ordered hexagonal ferrites with A2-type spin configuration have been intensely studied due to their potential for room-temperature multiferroicity with strong magnetoelectric couplings. However, the subtle interplay between the magnetic structure and trimer structural distortion, which is a critical ingredient for ferroelectricity, has not been clearly verified in experiments due to the lack of control over trimer distortion. In this study, we report on Lu0.6In0.4FeO3, which exhibits weaker trimer distortion primarily related to the smaller tilting of the FeO5 bipyramids. The reduced vertical displacement of the equatorial oxygen of FeO5 located at the center of the trimer lowers the magnitude of the in-plane Dzyaloshinskii–Moriya vector component, resulting in the absence of canted ferromagnetism with the planar A1-type spin configuration, rather than the canted A2-type observed in other hexagonal ferrites. Our findings demonstrate that the degree of trimer distortion plays an important role in determining the spin configuration in related hexagonal systems. [ABSTRACT FROM AUTHOR]

Improper ferroelectricity and canted ferromagnetism in antiferromagnetically ordered hexagonal ferrites with A2-type spin configuration have been intensely studied due to their potential for room-temperature multiferroicity with strong magnetoelectric couplings. However, the subtle interplay between the magnetic structure and trimer structural distortion, which is a critical ingredient for ferroelectricity, has not been clearly verified in experiments due to the lack of control over trimer distortion. In this study, we report on Lu0.6In0.4FeO3, which exhibits weaker trimer distortion primarily related to the smaller tilting of the FeO5 bipyramids. The reduced vertical displacement of the equatorial oxygen of FeO5 located at the center of the trimer lowers the magnitude of the in-plane Dzyaloshinskii–Moriya vector component, resulting in the absence of canted ferromagnetism with the planar A1-type spin configuration, rather than the canted A2-type observed in other hexagonal ferrites. Our findings demonstrate that the degree of trimer distortion plays an important role in determining the spin configuration in related hexagonal systems. [ABSTRACT FROM AUTHOR]

Magnetic viscosity experiments have been performed in order to investigate the magnetization reversal in Sr nanoferrite particles (nanoscale SrFe12O19) and interacting Sr/Co nanoferrite particles (SrFe12O19–CoFe2O4 nanocomposites). The magnetic viscosity S = d M (t) / d l n (t) , where M (t) is the magnetization as a function of time, has been collected. For Sr nanoferrite S shows a maximum close to the coercive field, reflecting the relation between S and the energy barrier distribution. We evidence that magnetic viscosity experiments on Sr nanoferrite and interacting Sr/Co nanoferrite particles provide reliable qualitative results for the different magnetic field sweep rate and saturating field H s a t considered. In addition, the activation volumes extracted from the magnetic viscosity experiments performed at different temperatures on Sr nanoferrite are quantitatively correlated to anisotropy changes. [ABSTRACT FROM AUTHOR]

By adjusting the parameters in the additive manufacturing process, the optimization of the microstructure and mechanical properties of 2205 duplex stainless steel (DSS) is of great significance to ensure the reliability of the material in harsh environments. The 2205 DSS samples are prepared by cold metal transfer conditions of interlayer cooling time of 0, 30, 60, and 120 s, respectively, and the microstructure and properties of the samples are characterized in detail. With the increase of cooling time, the height of the samples increases, and the width decreases, and no defects are found in all the samples. It also reduces the grain size and contributes to the uniform distribution of grains. With the extension of cooling time, the proportion of austenitic phase gradually increases from 41.60% to 47.36%, while the proportion of ferrite decreases correspondingly. The mechanical properties of the samples are tested. With the increase of cooling time, the hardness of the samples increases from 646.32(±1.46) to 679.36(±7.27) MPa, and the ductility decreases from 60.10(±0.50)% to 43.67(±2.10)%. The results show that the interlayer cooling time can be used to regulate the formation, microstructure, and properties of DSS. [ABSTRACT FROM AUTHOR]

Effects of the cerium content on inclusions, microstructure, and performance of an Al‐killed low‐sulfur steel are studied. As the cerium content in the steel increases from 0 to 190 ppm, the evolution path of the inclusion composition is Al2O3→CeAlO3→Ce2O2S + Ce2O3, and the inclusion size first decreases and then increases. When the cerium content is 76 ppm, the inclusion size reaches the minimum value. The addition of the ferrocerium is beneficial to the grain refinement of the Al‐killed low‐sulfur steel due to the low disregistry between inclusions and the steel matrix. The grain size of the steel decreases first, and it changes little after the cerium content reaching 76 ppm. The grain refinement is beneficial to increase steel properties. However, excessive inclusions in steel with a high cerium content reduce the tensile strength and the plasticity of the Al‐killed low‐sulfur steel. [ABSTRACT FROM AUTHOR]

ABSTRACT Low‐power magnetic coupling resonant wireless power transfer (MCRWPT) systems are less efficient at long transmission distances due to magnetic leakage and losses. For this reason, combining ferrite‐nanocrystalline hybrid shielding and a relay coil, an improved MCRWPT system based on the LCC‐LCC compensation network is designed in this paper. Firstly, the transmission performance of the MCRWPT systems with S‐S and LCC‐LCC compensation networks are compared and analyzed. Secondly, the transfer efficiencies of the MCRWPT system are analyzed when the relay coil is added at different locations, and the transfer efficiencies of the system with single material shielding are compared. Finally, the transmission performance of the MCRWPT system with ferrite‐nanocrystalline hybrid shieling is analyzed using simulation and experiment. Experimental results show that the transfer efficiency of the low‐power MCRWPT system using relay coil and hybrid shielding increases from 40.38% to 69.17% when the input voltage is 40 V and the transmission distance is 250 mm. Compared with the MCRWPT system based on ferrite full shielding, the weight of the MCRWPT system has been reduced by 63.11%. The hybrid shielding method not only improves the transfer efficiency of the MCRWPT system and reduces its spatial magnetic leakage but also has certain cost advantages. [ABSTRACT FROM AUTHOR]