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Magnetometers have received considerable attention in recent years. Magnetic components offer an alternative methodology to improve the sensitivity. Due to their exceedingly small structural dimensions, metasurfaces exhibit significant competitiveness in field modulation. A magnetic field concentration phenomenon of spheres at the nanoscale is presented in this paper. The sensitivity of a magnetometer is, therefore, improved through the enhanced static or quasistatic magnetic field by the nanosphere concentrator. Magnetic field redistribution due to the assistance of nanospheres is discussed in this paper using the finite element method. The numerical method is verified with classical analytical equations with a single sphere. The simulation results show that the magnetic field concentrates in the near field behind the nanosphere along the direction of the magnetic flux density. The radius, material or permeability exactly, and distribution are critical parameters to the concentration strength. The magnetic gain of a single nanosphere with typical positive permeability of the typical soft magnetic material reaches 3, and thus, the field along the magnetic flux direction concentrates. Furthermore, the amplification factor is more prominent with the nanosphere arrays compared to a single sphere with the same scale of size, and amplification improves with the sphere numbers and distributions in the array arrangement, which provides a novel approach for the designing of the magnetic flux concentrator being monolithically integrated with the magnetometer probe. Our simulation results provide a new degree of freedom by using nanoscale structures to manipulate magnetic fields. [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]

Soft magnetic materials are a core element of power electronics and electrical machines. However, none of the soft magnetic materials is able to exploit the full potential of wide bandgap semiconductors, which operate above MHz frequency for efficient energy conversion in power electronic systems. Here, a high‐performance Fe–Si soft magnetic composites with a 2D ordered domain structure are reported, enabling efficient energy conversion at MHz frequencies. By transforming spherical particles into flakes and arranging them in layers, 2D magnetic domains are created within the composite. This leads to a 90% increase in permeability and a tenfold decrease in loss at 3 MHz compared to composite made with spherical particles. The significantly increased cut‐off frequency indicates that the ordered flaky particles are suitable for MHz applications, unlike the disordered spherical particles. These findings provide an effective approach for fabricating high performance soft magnetic composites from traditional spherical particles and miniaturizing magnetic devices for efficient power electronics operation. [ABSTRACT FROM AUTHOR]

We are entering an era of re-electrification, seeking high-power density electrical machines with minimal resource use. Significant performance gains in electrical machines have been achieved through precise manufacturing processes, including the shaping/cutting of soft magnetic materials. However, most studies have evaluated magnetic performance at a macro level, focusing on components, while the fundamental mechanisms, e.g., how the micromagnetic behaviour is affected by mechanical interference, remain unclear. In this study, we examine the impact of sub-micron deformations at opposing strain rates (10−2 to 101 s−1) on the micromagnetic behaviour of soft magnetic non-oriented electrical steel. Using a diamond probe to indent within a single grain of polycrystalline material at different velocities, we induce quasi-static and dynamic mechanical loading. Our analysis, employing magnetic force microscopy, transmission Kikuchi diffraction, and scanning transmission electron microscopy with a pixelated detector, reveals that magnetic texture disturbances rely on the time-dependent dislocation dynamics of the Fe-BCC material. Additionally, we compress micro-pillars to further investigate these effects under bulk-isolated deformation. These findings highlight the importance of considering even ultra-small loads, such as nano-indentations and micro-pillar compressions, in the manufacturing of next-generation electric machines, as they can affect magnetic texture and performance. Mechanical deformations affect magnetic properties of electrical steels, impacting machine efficiency. Here, authors demonstrate that sub-micron deformations at different strain rates alter micromagnetic behaviour of non-oriented electrical steel due to time-dependent dislocation dynamics. [ABSTRACT FROM AUTHOR]

With the rise of eco-friendly policies, advanced motor technologies are being developed to replace fossil fuel-based engines in the mobility industry. Axial flux motors, known for their ability to reduce size and increase output torque compared to radial flux motors, require different materials and manufacturing techniques. Specifically, the production of complex stator cores and segmented magnets presents significant challenges, often leading to higher costs. To address this issue, soft magnetic composite (SMC) materials, which offer greater design flexibility, are being explored for use in stator cores. However, soft magnetic composite materials exhibit lower permeability and saturation flux density compared to laminated silicon steel, resulting in reduced output torque and efficiency. This paper investigates the effects of stator geometry on axial flux motor performance and explores cladding core technology, which combines soft magnetic composite materials with silicon steel. By conducting finite element method (FEM) analysis to evaluate the output torque and efficiency based on the shape of the silicon steel within the cladding core, this study proposes an optimized cladding core design to enhance the efficiency and output torque of axial flux motors. [ABSTRACT FROM AUTHOR]

A preprocessing technique named "spiral annealing" was applied for the first time to magnetic microwires. In this process, the sample was arranged in a flat spiral shape during annealing, and subsequent measurements were conducted on the unbent sample with the induced stress distribution along and transverse to the sample. The research utilized both magnetic and magneto-optical methods. The anisotropy field magnitude in both the volume and surface of the microwire was measured, and for the first time, a direct correlation between the anisotropy field and the curvature of a spirally annealed microwire was established. Additionally, a connection between the type of surface domain structure and the degree of spiral curvature was identified. The preservation of the distribution of spiral annealing-induced magnetic properties both along and across the microwire is a key effect influencing the technological application of the microwire. The range of induced curvature within which a specific helical magnetic structure can exist was also determined. This insight links the conditions of spiral annealing to the selection of microwires as active elements in magnetic sensors. [ABSTRACT FROM AUTHOR]

The advanced soft magnetic material Fe-Co-Si ternary alloy has become a research hotspot in recent years due to its excellent balanced magnetic properties. When used in an environment where oceans and magnetic fields interact, the corrosion behavior of this alloy is currently not well understood. In this study, immersion experiments and electrochemical tests have been used to explore its corrosion behavior under conditions of no magnetic field, a uniform parallel magnetic field, and a vertical magnetic field with a magnetic field. The results indicate that the presence of a magnetic field accelerates corrosion while suppressing pitting and intergranular corrosion of the alloy. Moreover, compared to the perpendicular magnetic field, the impact is more pronounced when applying a parallel magnetic field due to the synergistic effect of Lorentz force and magnetic field gradient force. Additionally, the presence of Si elements affects the formation of Co oxide passivation film, which reduced the corrosion resistance of the alloy under both magnetic and non-magnetic field conditions. This finding contributes to filling the theoretical gap in the corrosion failure behavior of Fe-Co-Si alloy under magnetic field conditions. [ABSTRACT FROM AUTHOR]

Magnetic materials with zero hysteresis are posed to have a significant impact on sustainable energy conversion, electronics, and communication technologies. As the global market for soft magnetic materials continues to expand, driven by increasing demand in renewable energy, automotive, and power transmission sectors, it is important to design magnets that can be cycled under an external field reversibly and rapidly multiple times without a decay in magnetic response. However, designing magnets with small hysteresis has been a challenge because we do not fully understand its origins. In this article, I outline key research efforts investigating the fundamental mechanisms underpinning hysteresis in soft magnets and, highlight recent developments in the use of nonlinear analysis and nucleation barrier methods to predict coercivity in these materials. [ABSTRACT FROM AUTHOR]

In this paper, we explore the benefits of using a magnetostrictive component in a variable reluctance energy harvester. The intrinsic magnetic field bias and the possibility to utilize magnetic force to achieve pre-stress leads to a synergetic combination between this type of energy harvester and magnetostriction. The proposed energy harvester system, to evaluate the concept, consists of a magnetostrictive cantilever beam with a cubic magnet as proof mass. Galfenol, Fe81.6Ga18.4, is used to implement magnetostriction. Variable reluctance is achieved by fixing the beam parallel to an iron core, with some margin to create an air gap between the tip magnet and core. The mechanical forces of the beam and the magnetic forces lead to a displaced equilibrium position of the beam and thus a pre-stress. Two configurations of the energy harvester were evaluated and compared. The initial configuration uses a simple beam of aluminum substrate and a layer of galfenol with an additional magnet fixing the beam to the core. The modified design reduces the magnetic field bias in the galfenol by replacing approximately half of the length of galfenol with aluminum and adds a layer of soft magnetic material above the galfenol to further reduce the magnetic field bias. The initial system was found to magnetically saturate the galfenol at equilibrium. This provided the opportunity to compare two equivalent systems, with and without a significant magnetostrictive effect on the output voltage. The resonance frequency tuning capability, from modifying the initial distance of the air gap, is shown to be maintained for the modified configuration (140 Hz/mm), while achieving RMS open-circuit coil voltages larger by a factor of two (2.4 V compared to 1.1 V). For a theoretically optimal load, the RMS power was simulated to be 5.1 mW. Given the size of the energy harvester (18.5 cm3) and the excitation acceleration (0.5 g), this results in a performance metric of 1.1 mW/cm3g2. [ABSTRACT FROM AUTHOR]

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study explores the application of AncorLam HR (Höganäs, Sweden), a soft magnetic composite material, in the stator core of an axial flux permanent magnet drive motor. Building on previous research that provided mechanical and thermal properties of the material, the focus is on analyzing how the manufacturing process affects the motor core's shape. A bulk prototype was created based on case 3, which demonstrated the least deviation in density and internal stress. The prototypes were produced under the conditions of SPM 7 and 90 °C, and a heat treatment in a nitrogen atmosphere for 1 h, resulting in an average density error of 0.54%, confirming process effectiveness. A microstructural analysis using scanning electron microscopy (SEM) on Sample 2, with the highest density, confirmed consistency between simulation and prototype trends. Electron backscatter diffraction (EBSD) and X-ray diffraction (XRD) analyses revealed that the internal phase structure remained unchanged. Energy-dispersive spectroscopy (EDS) and transmission electron microscopy (TEM) identified the elimination of phosphorus (P) during molding, affecting the insulating layer, a critical factor for SMC materials. In motor simulations and actual measurements, the average torque was recorded as 37.7 N·m and 34.7 N·m at 1500 rpm and 27.7 N·m and 25.1 N·m at 2000 rpm, respectively. The torque comparison observed in the actual measurements compared to the simulation results indicates that the output loss increases in the actual measurements due to the deterioration of the insulation performance judged based on the microstructure evaluation. This study confirms the viability of using AncorLam HR in motor cores for electric vehicles and provides key data for improving the performance. [ABSTRACT FROM AUTHOR]

Reducing the saturation magnetostriction is an effective way to improve the performance of soft magnetic materials and reduce core losses in present and future applications. The magnetostrictive properties of binary Fe-based alloys are investigated for a broad variety of alloying elements. Although several studies on the influence of Cu-alloying on the magnetic properties of Fe are reported, few studies have focused on the effect on its magnetostrictive behavior. High pressure torsion deformation is a promising fabrication route to produce metastable, single-phase Fe-Cu alloys. In this study, the influence of Cu-content and the chosen deformation parameters on the microstructural and phase evolution in the Fe-Cu system is investigated by scanning electron microscopy and synchrotron X-ray diffraction. Magnetic properties and magnetostrictive behavior are measured as well. While a reduction in the saturation magnetostriction λs is present for all Cu-contents, two trends are noticeable. λs decreases linearly with decreasing Fe-content in Fe-Cu nanocomposites, which is accompanied by an increasing coercivity. In contrast, both the saturation magnetostriction as well as the coercivity strongly decrease in metastable, single-phase Fe-Cu alloys after HPT-deformation. [ABSTRACT FROM AUTHOR]

Soft magnetic composites (SMCs) are key materials in electronic devices. Conventional SMCs incorporate too much insulating material in order to reduce eddy current loss at high frequency, resulting in severe magnetic dilution and demagnetization field, which leads to deterioration of the magnetic performance. In this paper, ZnO precursor is homogeneously deployed on the surface of FeSiAl, which in situ generates a thin and dense Al2O3 layer on the surface of FeSiAl through the interfacial solid phase reaction between Al and O atoms during annealing process. Meanwhile, ferromagnetic ZnO layer is simultaneously obtained due to the loss of O. The formed Al2O3/ZnO layers effectively reduce power loss and endow high frequency stability with less influence on effective permeability. Finally, FeSiAl/ZnO‐0.4% SMC exhibits low power loss of 83.2 mW cm−3 (50 mT/100 kHz), high effective permeability of 92, and cut‐off frequency as high as 40 MHz. This study provides an efficient route for high performance SMCs and broadens high frequency application of soft magnetic devices. [ABSTRACT FROM AUTHOR]

The article introduces a novel roasting technique under a dynamic magnetic field (RDMF) that enables the rapid synthesis of MnB crystals, producing bulk and powder forms within seconds.

A class of transformable materials is introduced with magnetic defect‐defined switchable configurations. The soft material can be magnetically‐programmed to transform into various encoded patterns utilizing the rich interplay of magnetic interactions and instability phenomenon. The strategy allows us to break the limit of admissible configurations of the instability‐induced patterns that dictate the post‐transformation behavior. The phenomenon is experimentally realized in a material system consisting of periodically distributed magnetic inclusions in a soft matrix. The programmable magnetic interactions between the inclusions act as smart defects redirecting the material transformations to targeted geometric configurations. Moreover, the role of magnetic spacing and field strength is systematically investigated to map the transition between mechanically‐dominant and magnetics‐dominant instability patterns. Lastly, the idea of reconfigurable material design is showcased by embedding binary information in magnetic form, which can be read out through the unique repositioning of inclusions via the applied mechanical deformation. [ABSTRACT FROM AUTHOR]

Coatings play a crucial role in minimizing eddy current loss in soft magnetic composites (SMCs). The powder atomic layer deposition (PALD) technique was utilized to coat Fe–Ni–Mo soft magnetic powder in this study. The Al 2 O 3 coating fabricated via PALD enhanced corrosion resistance and reduced core loss in SMCs. Additional deposition cycles increased the resistivity of the Fe–Ni–Mo powder and the corrosion resistance of the Fe–Ni–Mo SMCs, indicating that the density and integrity of the amorphous Al 2 O 3 coating were enhanced. Thinner coatings (20 cycles) exhibited anodic passivation in corrosion, which was attributed to insufficient density. Nevertheless, an excessively thick coating (100 cycles) resulted in a decrease in effective permeability and an increase in hysteresis loss. The fabricated Fe–Ni–Mo SMCs (50 cycles) demonstrated a core loss of 603.1 mW/cm3 at 100 kHz/100 mT, coupled with an effective permeability of 108.5 and a Q value of 97.8 at 100 kHz. [ABSTRACT FROM AUTHOR]

The Co-based nanocomposite alloys exhibit promising magnetic properties suitable for high-temperature applications. However, their metastable microstructure, especially the intergranular amorphous phase, raises concerns regarding their stability in elevated temperature conditions. In this study, we investigated the case of the Co75.4Fe2.3Mn2.3Si2Nb4B14 alloy. Initially, we measured activation energies under non-isothermal annealing conditions using both the Kissinger and Ozawa methods, and then further measured local activation energies by the Ozawa method. The thermal stability of the amorphous phase below the secondary crystallization temperature was explored using isothermal DSC tests, and represented using a time-temperature-transformation (TTT) diagram. Subsequently, we conducted experimental examinations to explore the microstructure evolution and air oxidation behavior at 500°C for up to 20 days. During the 20-day annealing process, abnormal grain growth of secondary crystallization was observed, leading to a deterioration in the soft magnetic properties of the material. In the 20-day oxidized sample, we found that larger crystalline grains were concentrated at the center, while the surface retained nanosized crystalline grains embedded in the residual amorphous phase. This stabilized surface area offers excellent corrosion resistance in the long-term exposure of the nanocrystalline Co75.4Fe2.3Mn2.3Si2Nb4B14 alloy. [ABSTRACT FROM AUTHOR]

An Ni25Co20Cu10Fe25Mn20 high-entropy alloy (HEA) was produced using mechanical alloying. Similar to equiatomic NiCoCuFeMn alloy, a face-centered cubic single-phase nanocrystalline HEA was obtained after 28-h milling. The lattice parameter of this new HEA (0.360 nm) was slightly smaller than that of equiatomic alloy (0.361 nm). The crystallite size of the final product was ~ 9 nm, significantly finer than the values reported for the equiatomic HEAs. According to the analysis of the HEA powder particles' deformation behavior, the system operated in a ductile-brittle mode. The thermal behavior of prepared alloy, characterized by differential thermal analysis, was similar from that of equiatomic NiCoCuFeMn alloy. Similar to the equiatomic NiCoCuFeMn, the sluggish diffusion effect was not true for the Ni25Co20Cu10Fe25Mn20 HEA. Studying the magnetic behavior of Ni25Co20Cu10Fe25Mn20 HEA, using vibrating sample magnetometry, confirmed a soft magnetic behavior for this material like an equiatomic alloy. [ABSTRACT FROM AUTHOR]

Dexterity micromanipulation is a significant topic in the field of robotics. Herein, a novel robotic rotating microjoint controlled by an exogenous magnetic field based on magnetic programmable soft materials, which brings more dexterity to the micromanipulation task is proposed. First, the magnetic soft material is synthesized and the microjoint is manufactured. The maximum rotation angle and response time are characterized. Then the force analysis of the microjoint in a uniform magnetic field is performed and the relationship between the deformation bending angle of a microjoint and the magnetic field magnitude is first proposed. A sliding mode controller based on the deformation mechanism of microjoints and radial basis function neural network (DMRSMC) is proposed to achieve robust deformation control of the microjoint. The experiment that depicts the microjoint is able to achieve a maximum rotation angle of 22.16° and a response time of 16 ms. The DMRSMC controller performs angle control with higher accuracy than conventional SMC and PID controllers. Finally, a dexterous suction mechanism is developed by combining the microjoint with a soft micropipette needle to achieve dexterous grasping of zebrafish embryos with a 97% success rate and an orientation adjustment error is 1.36°. [ABSTRACT FROM AUTHOR]

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Nowadays, there is a global search for electromagnetic gadgets that are affordable, eco-friendly, and energyefficient. This motivates engineers and scientists to develop new materials or enhance those that already exist. Fe-based soft magnetic materials are a significant class of soft magnetic materials that are essential to many energy-related industrial applications, including motors, converters, and electric transformers. This article focuses on the general characterization of magnetic materials, their magnetic properties and the analysis of the influence of mechanical milling of Fe powders prepared by mechanical milling in two different sizes (sample 1 - smaller then < 400 µm and sample 2 greater than > 400 µm). The experimentally obtained hysterical curves of ground Fe powders are measured using the Vibratimg Sample Magnetometer (VSM). [ABSTRACT FROM AUTHOR]

Solid solution modulation is an ideal method for combining the advantages of different parent compounds while mitigating their disadvantages. Here, we investigated the thermal sensitivity, magnetic properties, and microwave absorption of MgxMn1−xAl2xFe2(1−x)O4 (0.2 ≤ x ≤ 0.8) spinel solid solution ceramics for application in multifunctional devices. The electrical transport and magnetic properties can be modulated by adjusting the solution ratio. The ceramics exhibit negative temperature coefficient characteristic. The B‐values from 5065–8056 K, suggesting accurate temperature measurements over a wide temperature range. As a type of soft magnetic material, it has a narrow hysteresis loop and high resistivity. Vector network analyzer studies indicate Mg0.2Mn0.8Al0.4Fe1.6O4 could be a candidate for microwave absorption in S‐band. This study successfully extends the applicability of MgxMn1−xAl2xFe2(1−x)O4 ceramics for high‐temperature thermistors and also confirms potential for multifunctional device. [ABSTRACT FROM AUTHOR]

Design and development of novel high entropy alloys (HEAs) having balance magnetic properties with other functional properties are vital for industrial applications of these alloys. In this study, a novel Co35Cr5Fe10Ni30Ti5Al15 HEA was synthesized through mechanical alloying and studied for phase evolution and its effects on magnetic properties with annealing at different temperatures. As-synthesized HEA has a major fcc phase with minor concentrations of bcc and R phases. The as-synthesized HEA is also annealed at different temperatures of 500, 700 and 900°C and found that the phase identity of formed phases maintained after annealing. However, for HEA annealed at 1000°C, slight amount of new σ-phase has formed along with initial phases. Values of Ms and Hc were found to be 75 emu g−1 and 18 Oe for as-synthesized Co35Cr5Fe10Ni30Ti5Al15 HEA. We found that after annealing at different temperatures, magnetic properties of Co35Cr5Fe10Ni30Ti5Al15 HEA show significant improvement. Co35Cr5Fe10Ni30Ti5Al15 HEA annealed at 900°C exhibited good soft magnetic characteristics with high Ms (99 emu g−1), low values of Hc (3.8 Oe) and Mr (0.45 emu g−1), as compared to other samples developed in the present study. Thus, designed and developed 900°C annealed Co35Cr5Fe10Ni30Ti5Al15 HEA can be further used for magnetic switching applications due to the high value of Ms and low value of Mr. [ABSTRACT FROM AUTHOR]

Nickel-doped manganese–magnesium ferrite (NixMn0.25-xMg0.75Fe2O4) was prepared using the auto-combustion method. X-ray diffraction patterns showed a single ferrite spinel phase in all the prepared samples. The crystallite size ranged from 24.30 to 28.32 nm, increasing with increasing the Ni content. The porous structure of all the samples was verified with a scanning electron microscope. FESEM images were used to confirm the production of spherical or semi-spherical nanoparticles with little change in particle size distribution. The study revealed that the nanoparticles were small enough to behave superparamagnetically. According to the magnetic tests conducted with the VSM at room temperature, the hysteresis loop region is practically non-existent, indicating typical soft magnetic materials. In addition, the conductance responses of the magnesium ferrite nanocomposite were measured by exposing it to the oxidizing gas (NO2) at different operating temperatures. The results showed that the sensor with the nano ferrite sample of (x = 0.20) has a good sensitivity of 707.22% as well as response and recovery times. [ABSTRACT FROM AUTHOR]

The detection of magnetic nanoparticles in a liquid medium and the quantification of their concentration have the potential to improve the efficiency of several relevant applications in different fields, including medicine, environmental remediation, and mechanical engineering. To this end, sensors based on the magneto-impedance effect have attracted much attention due to their high sensitivity to the stray magnetic field generated by magnetic nanoparticles, their simple fabrication process, and their relatively low cost. To improve the sensitivity of these sensors, a multidisciplinary approach is required to study a wide range of soft magnetic materials as sensing elements and to customize the magnetic properties of nanoparticles. The combination of magneto-impedance sensors with ad hoc microfluidic systems favors the design of integrated portable devices with high specificity towards magnetic ferrofluids, allowing the use of very small sample volumes and making measurements faster and more reliable. In this work, a magneto-impedance sensor based on an amorphous Fe73.5Nb3Cu1Si13.5B9 wire as the sensing element is integrated into a customized millifluidic chip. The sensor detects the presence of magnetic nanoparticles in the ferrofluid and distinguishes the different stray fields generated by single-domain superparamagnetic iron oxide nanoparticles or magnetically blocked Co-ferrite nanoparticles. [ABSTRACT FROM AUTHOR]

The coupling of magnetic, thermal and structural force fields exists in the design, manufacture and operation of the magnetic core of transformer and motor, which makes the experimental data obtained from the standard magnetic properties measurement inconsistent with the actual problem. In order to obtain the magnetic properties measurement data of soft magnetic materials such as electrical steel sheet under multiple physical factors, the magnetic circuit structure was improved on the basis of the standard single sheet tester. At the same time, anti-bending clips made of polyether ether ketone were installed in order to prevent the bending deformation of the sample sheet during the application of tensile stress which would lead to uneven force. Then0 this basic structure of the tester under the coupling of temperature and stress is designed. In order to further improve the excitation performance of the tester and the magnetization uniformity of the sample, combined with COMSOL and MATLAB co-simulation, adaptive genetic algorithm was used to optimize the size of the yoke and excitation coil, thereby ensuring the uniformity of the magnetic field distribution in the measurement area of the sample. Finally, by combining simulation and specific experiments, the loss measurement results of a single sheet tester under different ambient temperatures and different stresses are studied, which proves that the tester is feasible and accurate, and the variation law of complex magnetic characteristics of electrical steel sheets under multiple physical fields is summarized. [ABSTRACT FROM AUTHOR]

Spinel ferrites are vital in developing next-generation technologies with potential applications covering the medical, electronic, and material industries. Nickel-cadmium spinel ferrites are soft magnetic materials having lots of applications ranging from electronics and magnetic to sensors industries. Herein, we developed cadmium-substituted spinel ferrites (Ba 0·5 Ni 0.5-x Cd x Fe 2 O 4) and their nanocomposite with polymer polyvinyl alcohol (PVA). The results evidently indicate that the successfully developed Ba 0·5 Ni 0.5-x Cd x Fe 2 O 4, which also confirmed the loading of PVA onto the Ba 0·5 Ni 0.5-x Cd x Fe 2 O 4 materials. XRD results confirmed orthorhombic single-phase structure. The optimal particle size was 27.22 nm, and the minimum was 21.25 nm, respectively, as shown by Ba 0·5 Ni 0·1 Cd 0·4 Fe 2 O 4 (x = 0.4) and PVA composite of Ba 0·5 Ni 0·2 Cd 0·3 Fe 2 O 4 (x = 0.3). It was also observed that the composites showed lower particle size than nano-ferrites. Spectral analysis (Fourier Transform Infrared Spectroscopy) confirmed the formation of spinel ferrites by detecting the M − O bonds in the 400-800 cm−1 region. υ 1 and υ 2 were appeared in the range 560–609 cm−1 and 439-466 cm−1, corresponding to M-O. The average grain size of spinel ferrites was 0.55, 0.50, 1.03, and 1.31 μ m for Ba 0·5 Ni 0.5-x Cd x Fe 2 O 4 (x = 0.1, 0.2, 0.3, and 0.4) spinel ferrites. Dielectric parameters revealed that these materials are suitable for high-frequency devices due to their low dielectric loss, high quality factor, short relaxation time, and diverse responses. [ABSTRACT FROM AUTHOR]

High-sensitivity magnetic sensors are fundamental components in fields such as biomedicine and non-destructive testing. Flux concentration technology enhances the sensitivity of magnetic sensors by amplifying the magnetic field to be measured, making it the most effective method to improve the magnetic field resolution of magnetic sensors. Superconductors and high-permeability soft magnetic materials exhibit completely different magnetic effects. The former possesses complete diamagnetism, while the latter has extremely high magnetic permeability. Both types of materials can be used to fabricate flux concentrators. This paper compares superconducting and soft magnetic flux concentration technologies through theoretical simulations and experiments, investigating the impact of different structural parameters on the magnetic field amplification performance of superconducting and soft magnetic concentrators. This research is significant for the development of magnetic focusing technology and its applications in weak magnetic detection and other fields. [ABSTRACT FROM AUTHOR]

High‐performance soft magnetic materials are important for energy conservation and emission reduction. One challenge is achieving a combination of reliable temperature stability, high resistivity, high Curie temperature, and high saturation magnetization in a single material, which often comes at the expense of intrinsic coercivity–a typical trade‐off in the family of soft magnetic materials with homogeneous microstructures. Herein, a nanostructured FeCoNiSiAl complex concentrated alloy is developed through a hierarchical structure strategy. This alloy exhibits superior soft magnetic properties up to 897 K, maintaining an ultra‐low intrinsic coercivity (13.6 A m−1 at 297 K) over a wide temperature range, a high resistivity (138.08 µΩ cm−1 at 297 K) and the saturation magnetization with only a 16.7% attenuation at 897 K. These unusual property combinations are attributed to the dual‐magnetic‐state nature with exchange softening due to continuous crystal ordering fluctuations at the atomic scale. By deliberately controlling the microstructure, the comprehensive performance of the alloy can be tuned and controlled. The research provides valuable guidance for the development of soft magnetic materials for high‐temperature applications and expands the potential applications of related functional materials in the field of sustainable energy. [ABSTRACT FROM AUTHOR]

Inkjet printing of magnetic materials has increased in recent years, as it has the potential to improve research in smart, functional materials. Magnetostriction is an inherent property of magnetic materials which allows strain or magnetic fields to be detected. This makes it very attractive for sensors in the area of structural health monitoring by detecting internal strains in carbon fibre-reinforced polymer (CFRP) composite. Inkjet printing offers design flexibility for these sensors to influence the magnetic response to the strain. This allows the sensor to be tailored to suit the location of defects in the CFRP. This research has looked into the viability of printable soft magnetic materials for structural health monitoring (SHM) of CFRP. Magnetite and nickel ink dispersions were selected to print using the JetLab 4 drop-on-demand technique. The printability of both inks was tested by selecting substrate, viscosity and solvent evaporation. Clogging was found to be an issue for both ink dispersions. Sonicating and adjusting the jetting parameters helped in distributing the nanoparticles. We found that magnetite nanoparticles were ideal as a sensor as there is more than double increase in saturation magnetisation by 49 Am2/kg and more than quadruple reduction of coercive field of 5.34 kA/m than nickel. The coil design was found to be the most sensitive to the field as a function of strain, where the gradient was around 80% higher than other sensor designs. Additive layering of 10, 20 and 30 layers of a magnetite square patch was investigated, and it was found that the 20-layered magnetite print had an improved field response to strain while maintaining excellent print resolution. SHM of CFRP was performed by inducing a strain via bending and it was found that the magnetite coil detected a change in field as the strain was applied. [ABSTRACT FROM AUTHOR]

Among soft magnetic materials, non-grain-oriented electrical steel (NGOES) has emerged as a promising option for various applications. NGOES material plays a crucial role across the entire energy value chain, spanning from power generation through generators to the consumption of electrical energy in electric motors and appliances within the electrical components industry which can lead to a notable enhancement in the performance of electric motors. NGOES are widely used for soft magnetic applications due to their cost and also their superior magnetic properties, including high electrical resistivity, excellent saturation magnetization, and minimal magnetostriction. NGOES are anticipated to serve as a driving force in the future global market for electric power consumption. The magnetic properties of NGOES are profoundly influenced by metallurgical factors such as Si content, grain size, crystallographic texture, sheet thickness, and surface roughness. These crucial variables play a crucial role in shaping the magnetic characteristics of NGOES materials which will be covered in this review paper. This paper provides an overview of different manufacturing routes for NGOES, as well as the advantages and disadvantages of these processes. Moreover, alternative manufacturing techniques and their capability to optimize the microstructure and to fabricate high Si NGOES sheets are discussed. Also, it addresses the challenges associated with mass-producing materials with high Si content using traditional methods. These advancements in this area present promising opportunities for enhancing the manufacturing processes of NGOES and ultimately enhancing the performance of future electrical machines and generators. [ABSTRACT FROM AUTHOR]

The paper focuses on an extension of the GRUCAD hysteresis model. The extension relies on the re- placement of the Langevin function with a more general Brillouin function in an equation describing the anhysteretic curve. The proposed approach allows one to obtain better fitting capabilities for anisotropic soft magnetic materials, as demonstrated by the example of hysteresis curves of grain-oriented electrical steel. [ABSTRACT FROM AUTHOR]

The purpose of the following paper is to compare the applicability of Rayleigh hysteresis model and Steinmetz law in the evaluation of power losses of selected soft magnetic materials under the influence of low magnetizing fields. Both approximations are relatively simple in terms of computational complexity, thus they seem to be appropriate for technical applications that do not require extensive knowledge of the physical properties of the material. The selected soft magnetic materials, i.e., steels and ferrites, in the form of toroidal cores, were investigated in low magnetizing fields with a computer-controlled hysteresisgraph system. Both considered models were applied to the obtained power loss characteristics. The quality of the description provided by each model was compared in terms of root-mean-square deviation and determination coefficient R², which allowed us to choose the more suitable approximation. [ABSTRACT FROM AUTHOR]

The article discusses a novel procedure for measuring the anhysteretic curve in soft magnetic materials. This curve frequently finds use in diverse applications, such as the Jiles-Atherton hysteresis model. The actual method is characterized in detail, including sample calculations for materials exhibiting various hysteresis loop shapes (ferrites, grain-oriented steel, and nanocrystalline material). To illustrate the benefits of the proposed approach, the authors compare the measurement-based and the simulated curves, the latter being obtained through an optimal interleaving of the model. [ABSTRACT FROM AUTHOR]

This paper focuses on two models used for the determination of power loss components in steel samples under dynamic magnetizing conditions. The considered models differ in their approach as far as the possibility of distinguishing bulk and localized eddy currents is concerned. Two samples of non-oriented electrical steel differing in silicon weight contents are the subject of experiments. A comparison of the obtained results, as well as their discussion, is given in the paper. [ABSTRACT FROM AUTHOR]

Stainless steel grade 430 is a type of soft magnetic electromagnetic material with rapid magnetization and demagnetization properties. Considering the delay phenomenon during operation, this study selected 430 stainless steel as the material and explored various metallurgical methods such as magnetic annealing and the addition of Mo as well as increasing the Si content to investigate the microstructure, mechanical behavior, and magnetic properties of each material, aiming to improve the magnetic properties of 430 stainless steel. Experimental results showed that the four electromagnetic steel materials (430F, 430F-MA, 434, and KM31) had equiaxed grain matrix structures, and excellent tensile and elongation properties were observed for each specimen. Additionally, the magnetic properties of the 430F specimen were similar under the DC and AC-10 Hz conditions. According to the hysteresis curves under different AC frequencies (10, 100, 1000 Hz), both magnetic annealing and the addition of Mo could reduce the Bm, Br, and Hc values of the raw 430F material. Increasing the Si content resulted in a decrease in Hc values and an increase in Bm and Br values. [ABSTRACT FROM AUTHOR]

The synthesis of Fe/TiO2 nanocomposite soft magnetic materials, incorporating Cu, Fe2O3, and Cu/Fe2O3;, was achieved using the mechanical alloying technique. Advanced characterization methods, including Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), X-ray Diffraction (XRD), and Vibrating Sample Magnetometer (VSM), were employed for a comprehensive investigation of structural, morphological, and magnetic properties of the nanocomposite at different synthesis stages. The crystallite size reaches its minimum value, while the lattice strain (ε) attains its maximum value in the FeCu/TiO2 nanocomposite, measuring 26.85 nm and 0.35%, respectively. Coercivity, magnetic remanence, and squareness ratio of Fe/TiO2 showed an upward trend with increasing milling time, reaching peak values after 5 h of milling. The FeTiO2 nanocomposite achieved maximum values for coercivity, magnetic remanence, and saturation magnetization. Notably, the squareness ratio demonstrated notable values for both FeTiO2 and FeCuTiO2. [ABSTRACT FROM AUTHOR]

Screen printing enables the production of very thin magnetic sheet laminations in near net shape geometry. This minimizes material waste in production and simultaneously reduces losses during machine operation and in-creases geometric design freedom. The subsequent sintering process step is particularly relevant, since the geometrical and magnetic properties are defined, and relevant process costs are caused by the heat treatment. This paper presents the requirements of the debinding and sintering process for magnetic sheets and identifies relevant influencing factors to achieve defined product specifications in multiple iterations, using design of experiments. It focuses on the influencing factors furnace atmosphere, sintering temperature, holding time and stacking height and their impact on the magnetic and geometric properties of sintered magnetic sheets. [ABSTRACT FROM AUTHOR]

The paper presents the results of research from the analysis of primary magnetization curves for Fe based amorphous alloys. Structural defects in the form of pseudodislocation dipoles occur in amorphous alloys. Using the theory developed by H. Kronmuller called the approach to ferromagnetic saturation, it is possible to indirectly observe internal stresses occurring in the volume of amorphous alloys. The magnetic structure is sensitive to all kinds of inhomogeneities that become visible in the process of high-field magnetization. It has been shown that the cooling rate of the liquid alloy has a great influence on the migration of atoms during the solidification process. Longer time of alloy formation causes more atoms to occupy ordered positions, which results in a change in the distance between the magnetic atoms and a higher degree of structure relaxation. This is indicated by a significant difference in the value of the spin wave stiffness parameter Dspf. The structural differences of the alloys were also investigated using a magnetic balance. It has been shown that the cooling rate influences insignificant differences in the course of thermomagnetic curves and the Curie temperature.

This study aims to identify the optimal combination of process variables for laser powder bed fusion (LPBF) of electric motor (EM) cores using Fe–50Ni alloy. A thorough analysis of mechanical and magnetic properties, with a focus on its dynamic magnetic performance within 50–500 Hz frequency range, is presented. Optimized process parameters yielded relative densities above 99%. In the as-built condition, high hardness (twice that of conventionally processed alloy) and high ductility (>30% at rupture) were achieved. The as-built samples demonstrated magnetic properties below the requirements, but significant improvement was observed in the semi-static magnetic properties after heat treatment, with acceptable coercivity (44 A/m) and maximum permeability (∼104) attributed to a notable reduction in geometrically necessary dislocations (GNDs) density. Heat treatment did not significantly reduce the total loss at high flux densities or elevated testing frequencies because the energy loss in the as-built microstructure is lower than what is expected due to the activation of more domain walls resulting in a homogeneous distribution of eddy currents. The superior semi-static performance of the optimum sample is related to its texture, which was more oriented toward the easy axis of magnetization in this alloy ( direction). This research demonstrates the LPBF process's potential for manufacturing electric motor soft cores, providing acceptable surface integrity, roughness levels, and desired coercivity and permeability. However, the high total loss, specifically at elevated frequencies, highlights the need for additional capabilities of LPBF, such as fabricating multi-materials, to mitigate energy losses without resorting solely to heat treatment.