Magnetic Hysteresis Properties Research Articles

An improvement of the Jiles-Atherton model at various magnetic field amplitudes using the example of Terfenol-D material

Jiles-Atherton (JA) model has been widely used to describe the magnetic hysteresis property of Terfenol-D material. However, the accuracy of the classic JA model is not convincing any more when it is employed to predict the magnetizations under various amplitudes of the applied magnetic fields. This paper measures the magnetic field and magnetization indirectly and approximates the measured results to the best of the classic static JA model. Then it shows that the JA model fails to describe the magnetic hysteresis effectively, especially in computing the hysteresis width. The high computational error is caused from inappropriate value of the pinning parameter to quantify the average energy required to break pinning site. Then the parameter is modified from the constant value to an independent variable on the field amplitude. From the comparisons on the results of the maximum magnetization, maximum magnetization, residual magnetization and coercivity, the performance in describing the hysteresis property of Terfenol-D is obviously promoted by the improved model apparently compared to the classic one.

Frequency- and Temperature-Dependent Uncertainties in Hysteresis Measurements of a 3D-Printed FeSi wt6.5% Material.

Additive manufacturing of soft magnetic materials is a promising technology for creating topologically optimized electrical machines. High-performance electrical machines can be made from high-silicon-content FeSi alloys. Fe-6.5wt%Si material has exceptional magnetic properties; however, manufacturing this steel with the classical cold rolling methodology is not possible due to the brittleness of this material. Laser powder bed fusion technology (L-PBF) offers a solution to this problem. Finding the optimal printing parameters is a challenging task. Nevertheless, it is crucial to resolve the brittleness of the created materials so they can be used in commercial applications. The temperature dependence of magnetic hysteresis properties of Fe-6.5wt%Si materials is presented in this paper. The magnetic hysteresis properties were examined from 20 °C to 120 °C. The hysteresis measurements were made by a precision current generator-based hysteresis measurement tool, which uses fast Fourier transformation-based filtering techniques to increase the accuracy of the measurements. The details of the applied scalar hysteresis sensor and the measurement uncertainties were discussed first in the paper; then, three characteristic points of the static hysteresis curve of the ten L-PBF-manufactured identical toroidal cores were investigated and compared at different temperatures. These measurements show that, despite the volumetric ratio of the porosities being below 0.5%, the mean crack length in the samples is not significant for the examined samples. These small defects can cause a significant 5% decrement in some characteristic values of the examined hysteresis curve.

Synthesis and Magnetic Hysteresis Properties of an Aluminum-Doped Isotropic Hard-Magnetic Fe–Cr–Co Powder Alloy

Synthesis and Magnetic Hysteresis Properties of an Aluminum-Doped Isotropic Hard-Magnetic Fe–Cr–Co Powder Alloy

A Particle-Swarm-Optimization-Algorithm-Improved Jiles–Atherton Model for Magnetorheological Dampers Considering Magnetic Hysteresis Characteristics

As a typical intelligent device, magnetorheological (MR) dampers have been widely applied in vibration control and mitigation. However, the inherent hysteresis characteristics of magnetic materials can cause significant time delays and fluctuations, affecting the controllability and damping performance of MR dampers. Most existing mathematical models have not considered the adverse effects of magnetic hysteresis characteristics, and this study aims to consider such effects in MR damper models. Based on the magnetic circuit analysis of MR dampers, the Jiles–Atherton (J-A) model is adopted to characterize the magnetic hysteresis properties. Then, a weight adaptive particle swarm optimization algorithm (PSO) is introduced to the J-A model for efficient parameter identifications of this model, in which the differential evolution and the Cauchy variation are combined to improve the diversity of the population and the ability to jump out of the local optimal solution. The results obtained from the improved J-A model are compared with the experimental data under different working conditions, and it shows that the proposed J-A model can accurately predict the damping performance of MR dampers with magnetic hysteresis characteristics.

The magnetocaloric effect properties for potential applications of magnetic refrigerator technology: a review.

In the pursuit of a clean and environmentally friendly future, magnetic refrigerator technology based on the magnetocaloric effect has been proposed as a replacement for conventional refrigeration technologies characterized by inefficient energy use, greenhouse gas emissions, and ozone depletion. This paper presents an in-depth exploration of the current state of research on magnetocaloric effect (MCE) materials by, examining various types of MCE materials and their respective potentials. The focus is particularly directed towards perovskite manganite materials because of their numerous advantages over other materials. These advantages include a wide working temperature range, easily adjustable Curie temperature around room temperature, excellent chemical stability, cost-effective production processes, negligible magnetic and thermal hysteresis properties, as well as competitive values for -ΔSM and ΔTad compared to other materials. Additionally, crucial parameters defining the MCE properties of perovskite manganite materials are comprehensively discussed, both at a fundamental level and in detail.

5-Fluorouracil-loaded designed praseodymium oxide – poly- β-cyclodextrin nanorods for effectively inhibiting breast cancer cells

Breast cancer remains one of the commonly prevailing and challenging diseases. Lanthanide-based nanomaterials are fascinating depending on their unique properties and represent a preferable choice of drug transport, aimed at finding an agent for targeted therapy. It necessitates that lanthanide-based nanocarriers with suitable surface modification and desired physicochemical characteristics are developed for effective anticancer drug delivery, owing to their fascinating light absorption, magnetic, and morphological features. Herein, we report praseodymium oxide nanorods in combination with poly-cyclodextrin as a novel nanocarrier to deliver the chemotherapeutic drug 5-fluorouracil to breast cancer cells. The praseodymium oxide nanoparticles were prepared using a sonochemical method and characterized using routine analytical methods, including X-ray Diffraction, Transmission Electron Microscopy, and X-ray Photoelectron Spectroscopy. The monodisperse rod-shaped structures possess length and width of 200 ± 30 and 72 ± 10 nm, respectively. The nanoparticles are 64.33% crystalline, revealed by XRD. The polymer content in the nanoparticles is ∼37% by weight. Further, the nanoparticles' magnetic, light absorption and photoluminescence characteristics are studied. Low saturation magnetization and insignificant hysteresis properties are observed. Broad absorption and visible wavelength region photoluminescence arise from the praseodymium in the material. The continuous release of the drug cargo and the in vitro anticancer activity are discussed. The loaded drug (5-fluorouracil) is released sustainably, extending over 250 hours. The anticancer activity in vitro is observed with the portion of the drug released from the nanocarrier. The apoptotic action mode of the drug-carrier vehicle is analyzed. The inhibition of cells occurs mainly on the S-phase of the cell cycle. The nanomaterial can function as a drug carrier and is suitable for anticancer therapy. The results reported herein on praseodymium oxide nanoparticles are promising as a nanocarrier and pose the possibility of future in vivo studies.

Magnetic Hysteresis Properties of Isotropic Hard Magnetic Fe–Cr–Co Compositions Alloyed with Tungsten

Magnetic Hysteresis Properties of Isotropic Hard Magnetic Fe–Cr–Co Compositions Alloyed with Tungsten

Dynamic magnetic hysteresis features of a mixed spin (2, 5/2) Ising system on a hexagonal lattice under an oscillating magnetic field within the path probability method

Recently, we [J. Magn. Magn. Mater. 514 (2020) 167242] presented a study of the dynamic magnetic loop features of molecular-based magnetic materials and ferrimagnetism that were investigated by using a mixed spin 1/2 and spin-1 ferrimagnetic Ising system within the path probability method. We found several interesting dynamic magnetic hysteresis properties and observed that the obtained results are in qualitatively good agreement with some theoretical and experimental studies in magnetic materials. We extended our recent previous published work to study the dynamic magnetic hysteresis properties of molecular-based magnetic materials and ferrimagnetism utilizing the mixed spin (2, 5/2) ferrimagnetic Ising system on a hexagonal lattice employing the path probability method. The spin (2, 5/2) Ising system is one of the most suitable and most used prototypical systems to investigate many molecular-based magnetic materials and ferrimagnetic materials. We found more interesting dynamic magnetic hysteresis properties such as double, triple, quadruple and quintuple loop behaviors for the layer magnetization, and only double and triple loops for the total magnetization. We found that some of our obtained results are in qualitatively good agreement with some theoretical, experimental reported works, and the works on some magnetic materials as obtained by the melt-spinning technique.

Physical properties of Fe–Ag–Pt films

Data are presented on the effect of high-frequency three-electrode ion-plasma sputtering and modernized three-electrode ion-plasma sputtering of a Fe–Ag–Pt complex target on the structure and properties of deposited films. The formation of nanocrystalline films with a size of the coherent scattering region of 3.5 nm during high-frequency ion-plasma spraying has been established. With the modernized three-electrode ion-plasma sputtering, a nanocrystalline phase is formed with a coherent scattering region size of 3 nm and higher temperature stability, up to 660 K. There were investigated the thermal stability of the metastable states of the Fe–Ag–Pt films; the electro- and hysteresis magnetic properties of freshly prepared and heat-treated films. The conditions for obtaining films with low values of the temperature coefficient of electrical resistance (∼5 × 10−5 K−1) and coercive force (Hc ∼ 12 kA/m) are determined.

A Dynamic Model for Prediction of Hysteresis and Loss Property of Soft Material Under Multiple Harmonic Magnetizations

This article presents an improved algorithm for identification of the excess loss statistical parameter to get more accurate prediction of multiple harmonic magnetic hysteresis and loss properties of grain-oriented silicon steel sheets. Magnetic hysteresis characteristics of a specimen are measured on a magnetic measurement platform. Static hysteresis property can be simulated accurately by the Preisach model. The excess loss field expression under multiple harmonic magnetizations is constructed based on an extraction algorithm for the statistical parameters of excess loss. According to the equivalence of loss separation and field separation, a new dynamic model is established. In the case of different multiple harmonic magnetizations, the magnetic hysteresis characteristics obtained by predictions are compared with the test results. Also, the influences of peaked flux density, harmonic order, and harmonic content upon the total iron loss are investigated.

Atomic Force Manipulation of Single Magnetic Nanoparticles for Spin-Based Electronics.

Magnetic nanoparticles (MNPs) are instrumental for fabrication of tailored nanomagnetic structures, especially where top-down lithographic patterning is not feasible. Here, we demonstrate precise and controllable manipulation of individual magnetite MNPs using the tip of an atomic force microscope. We verify our approach by placing a single MNP with a diameter of 50 nm on top of a 100 nm Hall bar fabricated in a quasi-two-dimensional electron gas (q2DEG) at the oxide interface between LaAlO3 and SrTiO3 (LAO/STO). A hysteresis loop due to the magnetic hysteresis properties of the magnetite MNPs was observed in the Hall resistance. Further, the effective coercivity of the Hall resistance hysteresis loop could be changed upon field cooling at different angles of the cooling field with respect to the measuring field. The effect is associated with the alignment of the MNP magnetic moment along the easy axis closest to the external field direction across the Verwey transition in magnetite. Our results can facilitate experimental realization of magnetic proximity devices using single MNPs and two-dimensional materials for spin-based nanoelectronics.

Design and Characteristic Analysis of an Inductive Link for Wireless Current Charging of a HTS Magnet

Laboratory electromagnets are a type of scientific instrumentation widely used to study physical characteristics such as magneto-optical, magnetic hysteresis, and susceptibility properties. In laboratory electromagnets, it is important to generate a high field stably while also reducing the weight. This can generally be achieved by improving the magnetic properties of the ferromagnetic material used for the iron yoke or by increasing the operating current density of the excitation coil. High-temperature superconducting (HTS) coils can generate higher magnetic fields with smaller volumes compared to the copper coils used in conventional laboratory electromagnets due to their high current-carrying capacities. However, when excitation current in conventional HTS coils is generally charged using a power-driven mode, a high heat transfer load from the busbar occurs. The heat transfer load to the HTS coil deteriorates the operational efficiency and stability of the electromagnet system. To mitigate this problem, this paper proposes an inductive link for wireless current charging for laboratory HTS magnets. A magnetic coupler for the inductive link is also designed in consideration of the coupling coefficient, and a resonance circuit and rectifier circuit are designed using elements whose operational characteristics were verified in a cryogenic environment. Evaluating the feasibility of the proposed method is carried out via a finite element analysis combined with an electrical circuit analysis.

Dynamic Hysteresis and Loss Modeling of Grain-Oriented Silicon Steel Under High-Frequency Sinusoidal Excitation

This article presents an improved dynamic hysteresis model to predict magnetic hysteresis properties under high-frequency sinusoidal excitations. A new expression of magnetic field strength related to classical loss is derived and proposed to consider the effect of skin effect on the iron loss. The permeability related to statistical parameter is presented to establish the relationship between classical loss and excess loss. The introduction of shape factor provides a possibility for accurate prediction of dynamic loops at high frequency over a broad induction range. The accuracy of the proposed dynamic hysteresis model is verified by comparing the predicted results with the measured ones. In addition, the variation of loss components with frequency and peaked induction is analyzed.

Specific loss power of magnetic nanoparticles: A machine learning approach

A machine learning approach has been applied to the prediction of magnetic hysteresis properties (coercive field, magnetic remanence, and hysteresis loop area) of magnetic nanoparticles for hyperthermia applications. Trained on a dataset compiled from numerical simulations, a neural network and a random forest were used to predict power losses of nanoparticles as a function of their intrinsic properties (saturation, anisotropy, and size) and mutual magnetic interactions, as well as of application conditions (temperature, frequency, and applied field magnitude), for values of the parameters not represented in the database. The predictive ability of the studied machine learning approaches can provide a valuable tool toward the application of magnetic hyperthermia as a precision medicine therapy tailored to the patient’s needs.

Experimental evaluation and theoretical analysis of the mechanical properties of ferromagnetic materials using the magnetic hysteresis properties

The magnetic hysteresis properties of ferromagnetic materials have been investigated by experimental measurement and theoretical analysis for mechanical property evaluation. A modified Jiles-Atherton (JA) model is proposed considering both the frequency and microscopic dependence of the hysteresis properties. Dynamic hysteresis experiments of ferromagnetic specimens with different hardness values were performed to measure the hysteresis loops. Microscopic measurements of the specimens were performed to obtain the grain size and dislocation density, which were introduced into the dynamic JA model to calculate the theoretical hysteresis loops. The genetic algorithm was used to inverse the basic parameters of the JA model by matching the theoretical hysteresis loops with the experimentally measured hysteresis loops. Two magnetic parameters (the coercivity and power-law coefficient) were extracted from the hysteresis loops for mechanical property evaluation of ferromagnetic materials. It was found that the proposed JA model can be used for theoretical analysis of the influence of the microstructure on the magnetic hysteresis properties, and the coercivity and power-law coefficient can be used for mechanical property evaluation of ferromagnetic specimens. The research reveals the influence of microstructure on the mechanical properties (hardness) and magnetic characteristic parameters of ferromagnetic materials.

Magnetic hysteresis properties of sol-gel synthesized Li-Co-Y ferrites

Li- Co-Y ferrites having the general formula Li0.495Co0.01YxFe2.485-xO4 where x ranges from 0.00 to 0.25 in steps of 0.05 were synthesized by chemical sol-gel auto combustion method. The sol-gel derived nanoferrite powders were initially heated at 300 °C for 1 h. The powders were then processed, shapped and heated at 1000 °C for 1 h using conventional furnace. The structural properties were studied using X-ray diffraction (XRD) technique and Fourier Transform Infrared (FTIR) Spectroscopy. The studies confirmed the formation of single phase with spinel structure in all the sol-gel synthesized ferrites. Scanning Electron Microscopy (SEM) studied the microstructure of the samples and found the formation of well defined grains. Vibrating Sample Magnetometer (VSM) measured the magnetic hysteresis properties of the prepared ferrites and found that saturation magnetization decreased but coercivity increased with Y3+ substitution. The results of the measurements obtained have been discussed in the paper.

Superparamagnetic Iron Oxide Nanoparticle Nanodevices Based on Fe3O4 Coated by Megluminic Ligands for the Adsorption of Metal Anions from Water.

The uptake ability toward arsenic(V), chromium(VI), and boron(III) ions of ad hoc functionalized magnetic nanostructured devices has been investigated. To this purpose, ligands based on meglumine have been synthesized and used to coat magnetite nanoparticles (Fe3O4) obtained by the co-precipitation methodology. The as-prepared hybrid material was characterized by infrared spectroscopy (IR), X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy combined with energy-dispersive X-ray analysis. Moreover, its magnetic hysteresis properties were measured to evaluate its magnetic properties, and the adsorption kinetics and isothermal models were applied to discern between the different adsorption phenomena. Specifically, the better fitting was observed by the Langmuir isotherm model for all metal ions tested, highlighting a higher uptake in arsenic (28.2 mg/g), chromium (12.3 mg/g), and boron (23.7 mg/g) sorption values if compared with other magnetic nanostructured materials. After adsorption, an external magnetic stimulus can be used to efficiently remove nanomaterials from the water. Finally the nanomaterial can be reused up to five cycles and regenerated for another three cycles.

Magnetization reversal processes in sintered permanent magnets Sm(Co, Fe, Zr, Cu)Z

The magnetic hysteresis properties of commercially available samples of sintered permanent magnets with the composition of Sm(Co0.796–xFe0.177CuxZr0.027)6.63 (x = 0.117 – 0.131) were investigated. To analyze the processes of magnetization and magnetization reversal, the magnetization curves from the thermally demagnetized state, major hysteresis loops, recoil curves, the dependence of the reversible magnetic susceptibility vs. magnetic fields strength, Kelly plots and angular dependences of the coercivity were used. These results indicate that magnetization reversal processes are more complicated than pinning. A model of magnetization reversal processes is proposed to explain why in some experiments the magnets exhibit a pinning mechanism of magnetization reversal and in some experiments a nucleation mechanism.

Magnetic Hysteresis Properties and Microstructure of High-Coercivity (Nd,Dy)–Fe–B Magnets with Dy less than 10 wt % and Low Oxygen

Magnetic Hysteresis Properties and Microstructure of High-Coercivity (Nd,Dy)–Fe–B Magnets with Dy less than 10 wt % and Low Oxygen

Studies of nanosized trivalent yttrium substituted lithium cobalt ferrites synthesized by sol-gel method

Trivalent yttrium substituted lithium cobalt ferrites having the general formula Li1+0.495Co2+0.01Y3+xFe3+2.495-xO2−4 where x ranges from 0.00 to 0.25 in steps of 0.05 were synthesized by chemical sol-gel method. The sol-gel derived ferrite powders were heated at 300 °C for 1 h using conventional furnace. Structure and phase were studied by X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). Scanning Electron Microscopy (SEM) and Vibrating Sample Magnetometer (VSM), studied the microstructural and magnetic hysteresis properties respectively of the prepared ferrites. The powders were pelleted and sintered at 1000 °C for 1 h and the same studies were carried out on these sintered ferrites. The results obtained have been discussed in the paper.