Reduction Of Hysteresis Loss Research Articles

The role of Cr in optimizing properties of Fe–B–C–P–Si–Mo–Cr metallic glasses for applications

With the rapid development of third-generation semiconductors, there is an urgent need to develop high-performance soft magnetic Fe-based metallic glasses tailored particularly for their high-frequency applications. In this work, new Fe76−yB7C7P7Si3Moy−xCrx (y = 0, 1, 2, 3 at.%, x ≤ y) alloys with relatively high glass-forming ability (GFA) were developed. The effects of replacing Mo with Cr on GFA, thermodynamic properties, soft magnetic properties, electrical resistivity (ρ), and corrosion resistance at different Fe contents were systematically studied. The possible causes of GFA variation were discussed. The results show that the addition of a small amount of Cr replacing Mo under different Fe contents would not lead to a decrease in GFA. The critical sizes of Cr-containing glassy alloys are 1–2.5 mm. These alloys possess relatively high saturation magnetization (Ms) of 1.29–1.41 T and lower coercivity (Hc) of 0.7–1.8 A/m, contributing to the reduction of hysteresis loss. In addition, Cr increases ρ of the alloys, reaching up to 162 μΩ cm, which is beneficial to reducing eddy current loss at high frequency. Furthermore, Cr effectively enhances corrosion resistance, thereby increasing the service life of the alloys in harsh environments. The role of Cr in these aspects makes it a beneficial element in soft magnetic metallic glasses for high-frequency applications.

Reduction of power loss in easy-plane FeSi soft magnetic composite under a weak bias magnetic field

This paper investigates the impact of a weak bias magnetic field (Hbias) along the easy magnetization plane direction on the power loss of easy-plane Fe-6.5 wt%Si (FeSi) soft magnetic composite (SMC). The results demonstrate that the power loss (Pcv) decreases by 18 % when the Hbias is 11.6 kA/m. Furthermore, it is found that the reduction in Pcv is not only attributed to decreases in hysteresis loss but also involves a decrease in excess loss. The causes of hysteresis loss and excess loss reduction are further investigated and it is found that the effect of the Hbias on the magnetization state plays an important role in the reduction of hysteresis loss. Additionally, the decrease in excess loss can be attributed to the reduction in local eddy current losses caused by non-uniform domain wall motion. These findings provide valuable insights for achieving high-frequency (MHz), high-efficiency, and miniaturized power electronic devices.

Multifunctional properties of transition metal based double perovskite ceramics

In this manuscript, iron based double perovskite oxides Ca2Fe1-xNixNbO6(x=0, 0.1) were successfully synthesized adopting the physical mixed oxide route and high temperature annealing. The influence of Ni substitution on the structure, band gap tuning, leakage current, dielectric, energy storage and magnetic properties of the parent ceramic is also discussed. A relatively high remnant polarization of 11.8 µC/cm2 with a reduced band gap of 1.9 eV is noticed in the Ni modified ceramic. It is found that the saturation magnetization increases from 0.359 emug−1 to 0. 892 emug−1 whereas the leakage current density decreases from 6.869E−6 to 5.52E-6 A/mm2 upon Ni substitution. The enhanced saturation magnetization and ferroelectric properties of the modified ceramic with lesser leakage current increases their energy storage capacity. The energy storage efficiency of the Ni substituted material increases from 15.52% to 71% with a reduction of hysteresis loss. Hence the increase in remnant polarization and decrease in band gap of the Ni modified ceramic aligns it toward ferroelectric photovoltaic application.

Martensitic Transformation, Magnetic and Mechanical Characteristics in Unidirectional Ni–Mn–Sn Heusler Alloy

A textured structure of Ni–Mn–Sn Heusler alloy with [001] preferred orientation has been grown by the directional solidification method. The crystal exhibits a single austenite phase L21 cubic structure (a = 5.997 Å) at room temperature. Magnetization and electronic transport measurements reveal the phase transformation characteristics. The maximum values of magnetic entropy change determined by Maxwell’s thermodynamic relation during the structural and magnetic phase transformations are 3.5 J/kg·K and −4.1 J/kg·K, and the total effective refrigerant capacity reaches about 314 J/kg (5 T). The evident reduction in hysteresis loss and broad operating temperature window provide a greater prospect for improving the cyclic stability of refrigeration and optimizing the application of such a magnetic refrigeration material. Both magnetoresistance (−18%, 5 T) and exchange bias field (302 Oe, 2 K) have also been investigated to understand the nature of phase transformations and exchange interactions. Furthermore, as the material exhibits excellent mechanical properties (1068 MPa, 9.0%), our experimental results provide a new reference for the application of Ni–Mn–Sn Heusler alloys.

Fatty acid modified cellulose: Preparation and application as green multi‐functional additive in a tyre tread formulation

AbstractThe increasing demand for biomass‐derived material and its usage in different forms in various commercial applications has become a need for sustainability. In this context, cellulose, the most abundant biodegradable material is modified (FAC) and used in tyre tread formulation. The potential of FAC is appraised against the lubricating nature of process oil due to its restricted usage for the presence of toxic polycyclic aromatic materials. In addition to that, Silane coupling agent is also replaced by FAC to assess its potency as a coupling agent. Multi‐functional nature of FAC is evaluated through morphological, rheological, physicomechanical, and dynamic‐mechanical means. Total replacement of oil with FAC has induced ~30–40% improvement in static modulus across elongation %age. Furthermore, improvement in grip properties (6%) along with a reduction in hysteresis loss (11%) is also portrayed by the composite having a complete substitution of oil by FAC. The efficacy of FAC as a potential replacement for SCA is also evaluated in this study. Replacement of 66% of SCA along with the complete substitution of oil with FAC has depicted comparable physicomechanical, dynamic as well as flow behavior with respect to the reference one. The introduction of fibrous structure along with intermolecular covalent bonding has reinforced FAC with multifunctional behavior. Thus, this multi‐functional behavior of FAC (reinforcing, dispersing, and coupling) can easily be applied in commercial tyre formulation facilitating a breakthrough in cheap and high‐performance biomass‐derived rubber composite.

Reduction of core loss for FeSi soft magnetic composites prepared using atomic layer deposition-based coating and high-temperature annealing

Using atomic layer deposition and high-temperature annealing to fabricate coatings for Fe-6.5 wt%Si powder reduce the hysteresis losses of the resultant composites drastically without sacrificing the permeability properties, and keep the eddy current losses at a relatively low value. The core loss of annealed FeSi SMCs is 39.67% lower than that of composites prepared using raw Fe-6.5 wt%Si powder, meanwhile the permeability remains at relatively high value (at B = 100 mT, f = 50 kHz). The decreasing of the core loss is mainly attributed to hysteresis loss reduction caused by grain growth. And the low eddy current loss is guaranteed by the uniform, complete, compact coating layer formed the surface of FeSi particles, which transforms to a protective and insulating layer containing silicate and metal oxide after annealing. On the premise of ensuring the integrity of the insulation layer, the annealing temperature of powder is significantly increased by surface modification, so as to reducing the hysteresis loss meanwhile controlling the eddy current loss. • Low core loss Fe-Si soft magnetic composites were prepared. • Nano-Al 2 O 3 was deposited on the surfaces of Fe-Si powders by ALD. • A protective and insulating layer formed at the interface after annealing. • Hysteresis loss reduced obviously due to the grain growth. • Decline of hysteresis loss dominates the dramatic reduction of total loss.

Reduction in Hysteresis Loss of Binder Jet Printed Iron Silicon With Boron

In this article, we use a factorial design of experiments to develop a three-way relationship between the 3-D printing parameters, the microstructural characteristics, and the hysteresis loss of binder jet printed iron silicon. Subsequent analysis of variance is used to validate the hypotheses between the printing process input factors and the output factors. The input factors in this work include the sintering temperature, the addition of boron, and the silicon content in the starting powder. The magnetic output factors of the printed iron silicon include the intrinsic coercivity and the hysteresis loss per cycle, which are extracted via the use of quasi-static magnetic characterization. Additionally, ac magnetic characterization is used to extract the total iron loss of the binder jet printed silicon. The microstructural output factors are extracted via the use of optical microscope. The established relationship can be used to reduce hysteresis loss in binder jet printed iron silicon.

Inductance Calculation of HTS Transformers with Multi-segment Windings Considering Insulation Constraints

High-temperature superconducting (HTS) transformers with multi-segment windings have been proposed in earlier literatures for the hysteresis loss reduction and short circuit electromagnetic force mitigation. The optimum distributive ratios for these multi-segment windings have been determined in earlier literatures. Asymmetrical seven segment winding with its optimum distributive ratio (k = 1/12) results in minimization of short circuit electromagnetic forces under normal tap and any adjusted tap. However, insulation design and leakage inductance calculation for the multi-segment winding of an HTS transformer have not been addressed in past literatures. Insulation design is one of the most crucial aspects in the transformer design, especially for high voltage power transformers. The analysis and optimization of the electric field distribution over the winding’s segments insulation in these HTS transformers provide the required dimensions for precise determination of the leakage inductances. In this paper, for the first time, winding insulation design and leakage inductance calculation of a 200 MVA, 230/20 kV HTS transformer with asymmetrical seven segment winding (and k of 1/12), are carried out. The analytical method besides a two-dimensional (2D) finite element method (FEM), through COMSOL Multiphysics software, is utilized for insulation design and calculation of leakage inductances of this transformer.

Hysteresis loss reduction in self-bias FeSi/SrFe12O19 soft magnetic composites

The magnetic field provided by magnetized SrFe12O19 particles in FeSi/SrFe12O19 composites is used to replace the applied transverse magnetic field, which successfully reduces the magnetic loss of the composites with minor reduction of permeability. This magnetic loss reduction mainly comes from the decrease in hysteresis loss, while the eddy current loss is basically unaffected. The hysteresis loss reduction in magnetized composites is believed to be due to the decrease in domain wall displacement caused by the increase in the average magnetic domain size in a DC magnetic field. This is an effective method for reducing the magnetic loss of soft magnetic composites with wide application potential, and there is no problem of increasing the cost and the volume of the magnetic cores.

Magnetic Properties of FeSiAl Soft Magnetic Composites under Transverse Magnetic Field

The magnetic properties of FeSiAl soft magnetic composites based on mechanically crushed powder are investigated under transverse magnetic field. Experimental results indicate that the permeability decreases about 8% when a transverse magnetic field is applied in the core, but the magnetic losses reduce more than 20%. Magnetic loss separation under low magnetic field shows that the loss reduction of the core under transverse magnetic field is mainly due to the reduction of hysteresis loss, and the hysteresis loss reduces about 45%. Magnetic loss separation under high magnetic field also gives similar results, and the hysteresis loss reduces about 31%. The reduction of hysteresis loss and permeability is attributed to the enlargement of domain size under transverse magnetic field. The enlargement of domain size leads to a decrease in the amount of domain walls participating in the wall displacement and makes the spin rotation more difficult; both these two effects result in reduction of hysteresis loss and permeability.

Reduction of hysteresis loss in soft magnetic composites under transverse magnetic field

A method to reduction hysteresis loss of soft magnetic composites (SMCs) is reported in this Letter. It is found that the power loss of SMCs reduces about 1/3 at the expanse of less than 10% decreases of permeability when a transverse magnetic field is applied in the SMC core. This power loss reduction comes from the decrease in hysteresis loss of composites, and this reduction is influenced by transverse magnetization state. This hysteresis loss reduction is attributed to domain wall displacements and spin rotations being completely locked in the direction of the transverse field, and this effect has great application potential in high-power electrical systems.

Hysteresis loss reduction and magnetocaloric effect improvement in the Ni-Co-Mn-In alloys

In this work the magnetocaloric effect (MCE) and hysteresis losses of Ni45Co5Mn(37-x)In(13+x) alloy (x= 0, 0.4) are studied. Also we propose a new approach in calculating the average entropy change to eliminate the overestimation of the magnetic entropy change calculation using Maxwell’s relations which is commonly seen in the indirect MCE calculation in the literature. The attributes of magnetostructural coupling have an important role in the magnetic behavior of these magnetofunctional alloys. This work exhibits that a strong magnetostructural coupling can be achieved over a wide temperature range in this alloy family which results in a higher MCE and relative cooling power (RCP) compared to other Ni-Mn-In based Heusler alloys. It’s shown that by increasing the applied field the peak of the entropy change curves shifts to lower temperatures. Additionally, a small variation in the stoichiometry composition broadens the magnetic entropy change curve and shifts the critical temperatures by about 36 K to around room temperature. Furthermore, due to the enhancement in ferromagnetic exchange interactions in austenite, the magnetization change accompanying the martensitic transformation is greatly improved, resulting in a large magnetic entropy change of 31 Jkg-1K-1 under 5T field. The broadened and higher peak of the entropy change curves produced a significantly high relative cooling power in Ni45Co5Mn36.6In13.4 (488 JKg-1) and Ni45Co5Mn37In13 (317 JKg-1) under 5T field. These results are especially promising in finding low-cost, high-performance magnetocaloric material for magnetic refrigeration systems.

Influence of Cr3+ substitution on structural, morphological, optical, and magnetic properties of nickel ferrite thin films

The NiFe2−xCrxO4 (0.0 ≤ x ≤ 1.0 in the step of x = 0.2) thin films have been synthesized using chemical spray deposition technique. The effects of Cr3+ content on the structural, morphological, optical and magnetic properties of these thin films have been investigated. The X-ray diffraction patterns confirmed single phase cubic spinel structure with space group of Fd-3m. The lattice constant decreases with increases Cr3+ concentration obeying Vegard’s law. The functional studied of Cr3+ substitution NiFe2O4 thin films were formed two major transmission bands, high-frequency band (ν1) around at 665 cm−1 is due to intrinsic vibrations of (A) site and the low frequency band (ν2) around 428 cm−1 is due to [B] site, respectively. Surface morphology was investigated in terms of root mean square roughness, average roughness (Ra), surface kurtosis and surface skewness of Ni–Cr ferrite thin films. The energy band gap for allowed direct electronic transition found to be in the range of 2.75–3.02 eV with Cr3+ content. According to VSM results show that, the saturation magnetizations of the thin film samples were found to be in the range of 234.12–46.65 emu/cc. The Cr3+ concentration increases with a reduction in hysteresis losses as well as slight reduction in the saturation magnetization.

Ni-Co-Mn-Sn quaternary alloys: Magnetic hysteresis loss reduction and ductility enhancement by iron alloying

Abstract The influence of Fe-alloying on the structural transition temperatures, microstructure, and mechanical and magnetocaloric properties of polycrystalline Ni41Co9−xFexMn40Sn10 (at. %) (x = 0–3) alloys has been studied. The substitution of Fe for Co introduced the so-called γ phase when the Fe content exceeds 1 at. %. The transformation temperatures decreased almost linearly with increasing Fe content without alteration of the transformation sequence. The compressive strength and maximum compressive strain increased to 1270 MPa and 21.3 % for Fe content of 3 at. %. In addition, the fracture type changed gradually from typical intergranular cracking to transgranular cracking with increasing Fe content. Magnetic field-induced reverse martensitic transformation was modified by increasing the Fe alloying, leading to the reduction of magnetic hysteresis loss (∼ 82.5 % drop after addition of 3 at. % Fe) but at the expense of a significant reduction in the maximum magnetic entropy change value.

Novel reduction of hysteresis loss controlled by strain memory effect in FeRh/PMN-PT heterostructures

As living standards increase, the energy consumption in refrigeration, such as air-conditioning and refrigerators, tremendously increases and intensifies global warming. As an alternative for the conventional vapor compression technique, solid state refrigeration based on magnetocaloric effect shows significant potential due to energy-saving and environmental-friendly properties. However, hysteresis loss is a longstanding problem seriously harming refrigeration efficiency. Here, we report novel enhancement of refrigeration efficiency controlled by strain memory effect in FeRh films grown on (011)-PMN-PT substrates. Utilizing nonvolatile strain triggered by a pulse electric field to engineer magnetization process of FeRh film, a nonvolatile large reduction of hysteresis loss, ∼56%, is achieved, consequently effective refrigeration capacity increases to ∼86%. The hysteresis loss can be expected to be eliminated and even turned out to be inverse through enhancing the strain memory effect. As a result, effective refrigeration capacity (RCeffe) can increase to a new height through introducing external mechanical work in a magnetic refrigeration cycle, and the ideal COP (coefficient-of-performance) would break through Carnot limit if only hysteresis loss and the contribution of mechanical work were considered.

Tailoring the Microstructure of Soft Magnetic Composites for Electric Motor Applications

Soft magnetic composite (SMC) material has been fabricated using 9 different powder particle fractions (smallest fraction: <;50 μm and largest: >400 μm). The microstructure features and resulting magnetic properties have been quantified and correlated. A specific focus lies on simultaneous consideration of the effects of particle size and internal grain size. Analysis has been carried out on samples in green condition and samples annealed between 400 °C and 600 °C. Electron backscatter diffraction technology brings about a substantially additional value to characterize deformations inside the grains. By detailed advanced microstructure analysis, it is shown that the deformation and recrystallization behavior is significantly different for different particle sizes used. Particle sizes between 100 and 200 μm show grain size distributions with the largest grains (d50 ~ 44 μm) in the volume of the particles resulting in the lowest hysteresis losses (PH ~ 4 W/kg, 1 T, 50 Hz). The relationship between particle and internal grain size distribution has been analyzed to enable further improvement of SMC materials concerning hysteresis loss reduction.

Comparative Characterization of Magnetic Properties of Textured Ni–5 at.%W Alloy Substrates

The hysteresis loss of Ni–5 at.%W (Ni5W) substrate contributes considerably to the alternating current (AC) loss of coated conductors (CCs) working at low transporting current or low-frequency field. In the present work, the evolution of texture and magnetic properties in Ni5W substrates is analyzed and also the relationship between magnetic properties and the extrinsic characteristics (evolved due to the processing techniques) is determined. By making the comparison, we discovered the magnetic domain structures of Ni5W substrates for the first time, achieving a strip/branched domain structures in the recrystallized substrates. The hysteresis loss has been decreased dramatically for the recrystallized substrates. Interestingly, we also observed that this loss is also related to the annealing temperature in the fully recrystallized substrates. The reduced loss can be mainly attributed toward the decrease of grain boundary, which proves the contribution of grain size toward the reduction of hysteresis loss. This result provides a new insight to tailor the hysteresis loss of Ni5W substrates used for coated conductors.

Properties of FeSiAl-based soft magnetic composites with AlN/Al2O3 and hybrid phosphate–silane insulation coatings

FeSiAl soft magnetic composites (SMCs), which are widely used in electromagnetic applications, can be described as FeSiAl particles surrounded by electrical insulating layers. In general, good insulation is required to minimize eddy currents within SMCs in high frequency applications. In this work, FeSiAl-based SMCs with uniform single insulation layer of AlN/Al2O3 were prepared by high-temperature selective nitridation and oxidation. For comparison, SMCs with double layers of phosphate-resin or phosphate-silane were produced by traditional chemical process. Their magnetic properties were systematically studied. The results revealed that the core insulated by AlN/Al2O3 with high electrical resistivity had much better stability in the real part of permeability μ′ than double layer insulated cores with respect to frequency in the range of 100 kHz to 28 MHz. In addition, the FeSiAl-AlN/Al2O3 core had higher quality factor Q at higher frequency than other cores. The investigation of the effects of annealing process up to 600 °C on the cores indicated that the magnetic properties of FeSiAl-AlN/Al2O3 cores were strongly improved in terms of μ′, Q, total core loss Ptot and coercivity HC mainly on account of the hysteresis loss reduction by stress relaxation and defects elimination. By contrast, annealing treatment had less positive effects on the properties of the cores with double insulating layer. In addition, the microstructure, composition and thermal stability of the AlN/Al2O3 insulated particles were characterized by Scanning Electron Microscopy, Transmission Electron Microscopy, X-Ray Diffraction, X-ray Photoelectron Spectroscopy and Derivative Thermogravimetric Analysis, respectively.

Giant magneto resistance and temperature coefficient of resistance in Sm0.55Sr0.30Ag0.15MnO3 perovskite

Silver ions substituted samarium strontium manganite (Sm0.55Sr0.30Ag0.15MnO3) pervoskite was synthesized by using respective oxides in stoichiometric ratio through solid state reaction. The as-prepared sample was characterized by various analytical techniques to confirm its formation and understand the effect of monovalent silver ions in pervoskite lattice. X-ray diffraction pattern confirms the single phase formation while grain morphology in SEM image indicates good connectivity among the grains. The enhancement in metal to insulator transition temperature shows quenched disorder and magnetoresistance phenomena. The magnetoresistance (MR) and temperature coefficient of resistance (TCR) emerge from grain growth factor and homogeneity induced by Ag+ ions in the lattice. The reduction in hysteresis loss resulted from antiferromagnetic - ferromagnetic (TN) and ferromagnetic - paramagnetic (Tc) transitions reveals the removal of disorder in perovskite lattice by Ag+ ions substitution. This increases the magnetic moment across distinct ions on the applying magnetic field. The rise in MR% (~99%) with silver doping emerging from smooth spin tunneling of the grains across the boundary and suppression of the disordered magnetic fluctuations with increase in magnetic field has been reported. The present compound exhibits the first order nature of magnetism and observed first time the highest value of TCR ~ 95%.

Electroless Plating: A Versatile Technique to Deposit Coatings on Electrical Steel

Coatings on grain-oriented electrical steel (GOES) are produced primarily by roller coating deposition of aluminum orthophosphate on the top of forsterite. These coatings provide the insulation resistance and stress to improve the magnetic properties. Electroless deposition of nickel- and cobalt-based coatings could be used as an alternative, because these coatings can be made insulated and stress can be generated and tailored in these coatings. The rate of deposition in electroless plating is faster when compared with other chemical coating techniques, and the process is autocatalytic (no external current required). The coatings are corrosion resistant, and the magnetic properties of the coatings can be varied by simply changing the pH of the solution. Addition of alloying elements, such as phosphorus and boron, can manipulate the stress generated in the coating from tensile to compressive and vice versa. A $2.15\pm 0.15~\mu \text{m}$ thick Co–Ni–P coating on GOES was able to reduce the power loss by 9%–11%. Similarly, a 414 ± 40 nm thick coating of Co–P-carbon nanotube (CNT) on GOES was able to reduce the power losses ranging 13%–15%. The reduction in power loss in a Co–Ni–P coated sample was due to the tensile stress applied to GOES by the coating that reduced the anomalous loss. The surface roughness was improved for both the Co–Ni–P and Co–P-CNT coatings. An improvement in the surface roughness contributed to the reduction of hysteresis loss.