Magnetic Properties Of Materials Research Articles

Magnetic Properties of Fe-Si Electrical Steel after Laser Scribing

Improvement of magnetic properties of electrical steel can be achieved by reduction the size of magnetic domains. The application of local stresses through laser scribing leads to reduced core losses. In order to determine the effect of laser refinement conditions of magnetic domains on the properties of the soft magnetic material, four samples with a thickness 0.23 mm were refined. The refinement of each sample was carried out using different line energies of the laser beam. Estimation of the magnetic domain size was performed using the Jeffries method, the magnetic viewer was used to reveal the domain structure. The measurement of the magnetic properties was performed at a frequency of 50 Hz and an induction of 1.5 T. The analyzed results presented in this work indicate impact of laser refining on magnetic properties of grain oriented electrical steel depending on used laser beam energy.

Giant Modulation of Refractive Index from Picoscale Atomic Displacements.

It is shown that structural disorder-in the form of anisotropic, picoscale atomic displacements-modulates the refractive index tensor and results in the giant optical anisotropy observed in BaTiS3, a quasi-1D hexagonal chalcogenide. Single-crystal X-ray diffraction studies reveal the presence of antipolar displacements of Ti atoms within adjacent TiS6 chains along the c-axis, and threefold degenerate Ti displacements in the a-b plane. 47/49Ti solid-state NMR provides additional evidence for those Ti displacements in the form of a three-horned NMR lineshape resulting from a low symmetry local environment around Ti atoms. Scanning transmission electron microscopy is used to directly observe the globally disordered Ti a-b plane displacements and find them to be ordered locally over a few unit cells. First-principles calculations show that the Ti a-b plane displacements selectively reduce the refractive index along the ab-plane, while having minimal impact on the refractive index along the chain direction, thus resulting in a giant enhancement in the optical anisotropy. By showing a strong connection between structural disorder with picoscale displacements and the optical response in BaTiS3, this study opens a pathway for designing optical materials with high refractive index and functionalities such as large optical anisotropy and nonlinearity.

Fabrication and Characterization of a Magnetic 3D‐printed Microactuator

AbstractConventional MEMS microactuators have, in recent years, been complemented by 3D‐printed actuatable microstructures fabricated via two‐Photon‐Polymerization (2PP). Herein, a novel compact 3D‐printed magnetically actuatable microactuator with a diameter of 500µm is demonstrated, originally designed for micro‐optical systems. It is fabricated by incorporating a composite of NdFeB microparticles and epoxy resin into a designated reservoir of the printed mechanical structure within a simple post‐processing step. The microactuator structure features mechanical springs, allowing for continuous positioning with large displacement. Mechanical studies by nanoindentation of IP‐S bulk structures reveal a viscoelastic material behavior, described by a two‐element General Kelvin‐Voigt viscoelasticity model. The obtained material parameters are then used to simulate and characterize the spring behavior of the microactuator. Actuation experiments are conducted using an external microcoil. The actuator displacement is measured for triangular current pulses with a peak current of 106 mA and durations of 1 to 100 s, resulting in displacements of 69.1 to 88.9 µm. Hysteretic behavior of the actuator is observed, attributable to viscoelasticity and magnetic properties of the core material. Numerical simulations of the experiment demonstrate this behavior as well. On‐the‐fly demagnetization and the implementation of closed‐loop control allow for both high repeatability and precise positioning.

Room temperature photosensitive ferromagnetic semiconductor using MoS2

Two-dimensional semiconductors, including transition metal dichalcogenides (TMDs), are of interest in electronics and photonics but remain nonmagnetic in their intrinsic form. Atomic modulation using physical and chemical ways is an effective means to control the physical properties such as magnetic and electrical properties of two-dimensional materials which can be controlled by irradiation. Here we treat mechanically exfoliated MoS2 with a helium ion beam, which exhibits semiconducting and ferromagnetic ordering at room temperature, while Monte Carlo simulations and theoretical calculations confirmed that the control of nanoholes result in the presence of magnetism. In addition, the irradiation results of multilayer MoS2 show that the magnetic moment increases with the increase of 10 layers. The conductivity remains virtually unchanged before and after being treated by a helium ion beam. The treated MoS2 spintronic device displays the switch of ‘on/off” under the light, magnetic field, and/or electric field, which means 2D photosensitive ferromagnetic semiconductor functions are successfully demonstrated at room temperature.

Physical Properties of Magnetic Materials of Cobalt Oxide, Iron Oxide and Manganese Oxide

This review focuses on the physical properties of three magnetic materials: Cobalt oxide (Co3O4), Iron oxide (FeO), and Manganese oxide (MnO). These materials exhibit interesting magnetic behavior and have been extensively studied due to their potential applications in various fields, including spintronics, magnetic storage, and magnetic sensors. In this review, we provide a comprehensive overview of the physical properties of Co3O4, FeO, and MnO, including their crystal structures, magnetic properties, structural properties, electrical properties, and thermal Properties. We also discuss the factors influencing the magnetic properties of these materials, such as temperature, doping, and external magnetic fields. Additionally, we highlight the technological applications and challenges associated with these magnetic materials. This review serves as a valuable resource for researchers and scientists interested in understanding and utilizing the physical properties of Co3O4, FeO, and MnO.

Magnetic behaviour of a mixed-spin ising model on a two-dimensional square-octagon lattice in a dynamic magnetic field

The magnetic behaviours of a two-dimensional square-octagon lattice with mixed spin 5/2 and spin 1 magnetic atoms are investigated in a dynamic magnetic field using effective field theory with correlations. We studied the effects of exchange coupling, anisotropy, oscillating magnetic fields, and temperature on the dynamic magnetic and thermodynamic properties of the square-octagon lattice. The dynamic magnetisation, order parameters, susceptibility, internal energy, and phase diagram of the system were obtained. These results significantly contribute to our understanding of the dynamic magnetic properties of two-dimensional materials. The ability to manipulate and control magnetic behaviour in two dimensions holds promise for the creation of more efficient and versatile devices.

GPTArticleExtractor: An automated workflow for magnetic material database construction

A comprehensive database of magnetic materials is valuable for researching the properties of magnetic materials and discovering new ones. This article introduces a novel workflow that leverages large language models for extracting key information from scientific literature. From 22,120 articles in the Journal of Magnetism and Magnetic Materials, a database containing 2,035 magnetic materials was automatically generated, with ferromagnetic materials constituting 76% of the total. Each entry in the database includes the material’s chemical compounds, as well as related structures (space group, crystal structure) and magnetic temperatures (Curie, Néel, and other transitional temperatures). To ensure data accuracy, we meticulously compared each entry in the database against the original literature, verifying the precision and reliability of each entry.

Investigation of mechanical properties of graphene-CNT reinforced nickel metal matrix nanocomposite structure

Nickel is a metal widely used in many industrial applications, but despite its superior properties, it also has some shortcomings. Carbon-based structures can be important reinforcement elements in improving the properties of metals. By providing a balance between the high corrosion resistance, high electrical conductivity and good magnetic properties of the nickel material and the lightness and high strength of carbon-based structures, a material with advanced properties can be obtained. Therefore, in this study, a new Nickel-Carbon nanostructure supported by a covalently bonded graphene-carbon nanotube (CNT) skeleton structure is presented. Additionally, three material designs with different geometric dimensions (Ni-G-CNT(5,5), Ni-G-CNT(10,10) and Ni-G-CNT(15,15)) were designed to determine the mechanical properties and properties of the structures in all directions. is to investigate the underlying deformation mechanisms. According to the results, it was observed that G-CNT structures increased the tensile and compressive behavior of the Ni structure in the CNT direction. For tensile loading in the CNT direction, as the CNT diameter decreases, the elastic modulus of the hybrid structures increases, while the maximum stress values are independent of the CNT diameter. As the CNT diameter increases, the ductility of the structures increases. In terms of compressive strength, it has been observed that in the linear region, as the CNT diameter increases, the strength generally increases and in the condensation region, it exhibits better compressive strength. With this study, an anisotropic nanostructure that is lighter and can exhibit higher tensile strength compared to the Ni structure is presented.

Effect of divalent metal ions substitution on the magnetic properties of Ba3Co2-xMexFe24O41 (Me = Zn2+, Ni2+) hexagonal ferrites

With the high-frequency development of communication technology, traditional communication materials have been difficult to meet the application requirements. Z-type hexagonal ferrite materials are widely used as good magnetic dielectric materials in high-frequency communication applications due to their high cut-off frequency and magnetodielectric properties. However, the high-frequency magnetodielectric properties need to be further improved, so the magnetic properties of the divalent metal ion-substituted Co2Z hexagonal ferrite materials are studied, and the anisotropy is calculated according to its static magnetic properties in this paper. A series of the ferrites Ba3Co2-xMexFe24O41(Me = Zn2+, Ni2+, where x = 0.0, 0.4, 0.8, 1.2, 1.6 and 2.0) were prepared by high-energy ball milling and sintering at 1260℃ for 3 h. The structural and magnetic properties of the samples were investigated using X-ray diffraction, vibrating sample magnetometer, and vector network analyzer. The studies indicated that the magnetic Ni2+ ions substitution increases the cutoff frequency, and the nonmagnetic Zn2+ ions substitution plays a positive role in increasing the magnetic permeability. Particularly, the Ba3Co1.6Ni0.4Fe24O41 and Ba3Co1.2Zn0.8Fe24O41 both have equal permeability and permittivity about 9 and 12, and their cutoff frequency exceed 2 GHz and 1 GHz, respectively. At the same time, these isomagnetic dielectric materials also have low loss, which will have great application potential in microstrip antennas.

Multifunctional Ce+3 doped nickel-cobalt mixed ferrites via co-precipitation method for photocatalytic and antibacterial activity

The overuse of industrial dyes and anti-bacterial drugs are destroying fresh water reservoirs and making bacteria more resistant, respectively. To sort out these problems, we have synthesized Cerium doped Nickel-Cobalt mixed ferrites (Ce-@NCMF) with chemical composition [Ni0.4Co0.6CexFe2-xO4 (where x = 0.00, 0.10, 0.15, 0.20 and 0.25)] via co-precipitation method. Influence of cerium doping on the structural, optical, electrical, magnetic, photocatalytic and anti-bacterial properties of Ce-@NCMF studied. Powder x-ray diffraction analysis (PXRD) confirmed the synthesis of Ce-@NCMF. Decrease of crystallite size from 29.71 to 24.95 nm was observed with increase in dopant concentration. Tauc’s plot indicated the decrease of energy bandgap from 2.10 to 1.89 eV with increase in dopant concentration, which revealed the absorption of light in visible region to generate electron–hole pairs for photocatalytic applications. FTIR spectra indicated the presence of M-O bonds as major functional group present in Ce-@NCMF. Electrical properties demonstrated the prominent increase of electrical conductivity with increase of Ce-doping. VSM analysis was performed to analyse the magnetic properties of materials and showed prominent decrease in saturation magnetization value from 84.66 to 19.85 emu g−1. Owing to optical bandgap in the visible region, all the synthesized samples were evaluated for their photocatalytic potential for the degradation of methylene blue. Ce-@NCMF at x = 25% dopant value showed maximum degradation efficiency (95%) under sunlight irradiation of 90 min. Kinetic studies of dye degradation followed pseudo-1st order kinetics with maximum rate constant (k) value of 2.78×10−2 min−1. Antibacterial activity results showed the bioactive nature of Ce-@NCMF against all strains of bacteria in consistent with the crystallite size of samples. Smallest crystallite size Ce-@NCMF were found most active against gram-negative bacterial strains.

Study on the magnetic shielding properties of nanocrystalline strips under bending stress

The study of the magnetic properties of nanocrystalline materials under stress is of great significance for the construction of small and lightweight magnetic shielding rooms. Therefore, this paper investigates the effect of stress on the magnetic properties of nanocrystalline materials under the action of external bending stress. By comparing the test results of the soft magnetic measuring device with and without bending stress, it is found that the magnetic permeability (μ i) decreases by about 51.41% when the introduced bending stress σ is increased by about 5.96 × 107 pa, whereas the KuFe−Si (induced magnetic anisotropy constant) and Hk (field of magnetic anisotropy) increase by 5.30 × 102 J m–3 and 1.08 × 102 A m−1, respectively. The Jiles-Atherton (J-A) model considering the bending stress and radius of change correlation is established, and the typical parameters of the J-A model are fitted using the Gazelle Optimization Algorithm (GOA), and the RMSE (root mean square error) of all of them are less than 0.056 T. The magnetic domain density increased with the increase of bending stress, which verified the correlation between the J-A model parameters and the bending stress. Our results reveal that the nanocrystalline macroscopic and micromechanical magnetic properties can be effectively combined with the J-A model, which will provide a theoretical basis for the simulation study of the nanocrystalline magnetic shielding device in the actual stress situation.

Magnon–phonon coupling modulation via dimensional reduction in thin antiferromagnet MnPSe3 nanoribbons

Two-dimensional (2D) magnetic materials have triggered tremendous interest in recent years due to their remarkable potential applications in magnetic storage and spintronics devices. Heat dissipation is of great significance in stability and durability of increasingly integrated magnetic devices. However, little investigation of thermal transport has been carried out in 2D magnetic materials and a comprehensive understanding of the underlying mechanism is still lacking. We experimentally demonstrate the thermal conductivity measurement of MnPSe3 nanoribbons and find a nonmonotonic thickness dependence, which is attributed to the phonon confinement effect in thin nanoribbons. The peaks of measured thermal conductivity are found to be modified with increasing thickness due to the magnon–phonon coupling. We propose that the magnon–phonon scattering rate increases with increasing thickness and causes a huge suppression in thermal conductivity. This study will deepen the understanding of the thermal properties of 2D magnetic materials and will benefit thermal management in designing magnetic devices.

Research on the Magnetic Properties of High-Saturation Magnetically Induced Alloy Motors under Magnetocaloric Coupling.

In the face of the rapid development of the motor industry, some motors with traditional soft magnetic materials can no longer meet the needs of the market. Using new high-saturation magnetic density materials has become a new breakthrough to improve the torque density of motors. Fe-Co alloys (1J22) have high-saturation magnetic induction strength, which can effectively improve the motor's magnetic field strength and increase its torque density. At the same time, the temperature rise of the motor is also an important factor to consider in the motor design process. In particular, the change in core temperature caused by loss makes the coupling of the internal temperature field and the electromagnetic field of the motor more common. Therefore, it is necessary to test the temperature and magnetic properties of 1J22 together. In this paper, a coupling measurement device for magnetic properties of soft magnetic materials is built, and a 1J22 temperature field-electromagnetic field coupling experiment is completed. It is found that the maximum loss of 1J22 decreases by 4.44% with the increase in temperature; the maximum loss is 6.41% less than that of traditional silicon steel. Finally, a finite element simulation model is built to simulate the actual working conditions of the motor, and it is verified that the magnetic properties of the material at high temperature will have a certain impact on the performance of the motor.

Application of Amorphous and Nanocrystalline Soft Magnetic Materials in Balanced-Force-Type Electromagnetic Relay.

The magnetic properties of soft magnetic materials, including their saturation magnetic induction strength and permeability, significantly affect the dynamic characteristics of electromagnetic relays. However, the soft materials most commonly used for relays in the magnetic conductive components of electromagnetic systems, such as electrical pure iron, limit further relay design improvement and optimization to a certain extent. Thus, this paper proposes the use of amorphous and nanocrystalline soft magnetic materials with good high-frequency magnetic properties in magnetic circuits. A wavelet analysis was conducted on the high-frequency components of the coil current while the relay operated, and the corresponding magnetic materials were selected. Considering the challenges in processing amorphous and nanocrystalline materials and collecting test data for the accuracy verification of simulation methods, we prepared a scaled-up prototype for use in dynamic characteristic tests. The simulation method was improved, yielding more accurate simulation results regarding the relay's dynamic characteristics. On this basis, six replacement schemes using amorphous and nanocrystalline materials were considered. The test results proved that this application could improve the relay's dynamic characteristics. Finally, a full-size sample with an iron core consisting of nanocrystalline alloy 1K107B was prepared, and the conclusions were verified in tests.

Magnetic State Control of Non-van der Waals 2D Materials by Hydrogenation.

Controlling the magnetic state of two-dimensional (2D) materials is crucial for spintronics. By employing data-mining and autonomous density functional theory calculations, we demonstrate the switching of magnetic properties of 2D non-van der Waals materials upon hydrogen passivation. The magnetic configurations are tuned to states with flipped and enhanced moments. For 2D CdTiO3─a diamagnetic compound in the pristine case─we observe an onset of ferromagnetism upon hydrogenation. Further investigation of the magnetization density of the pristine and passivated systems provides a detailed analysis of modified local spin symmetries and the emergence of ferromagnetism. Our results indicate that selective surface passivation is a powerful tool for tailoring magnetic properties of nanomaterials, such as non-vdW 2D compounds.

Magnetic, Dielectric, Electrical, Optical and Thermal Properties of Crystalline Materials

This Special Issue entitled “Magnetic, Dielectric, Electrical, Optical and Thermal Properties of Crystalline Materials” is devoted to a general overview of the subject of crystalline materials and may extend to the nanocrystalline field [...]

Single-Shot Laser-Induced Switching of an Exchange Biased Antiferromagnet.

Ultrafast manipulation of magnetic order has challenged the understanding of the fundamental and dynamic properties of magnetic materials. So far single-shot magnetic switching has been limited to ferrimagnetic alloys, multilayers, and designed ferromagnetic (FM) heterostructures. In FM/antiferromagnetic (AFM) bilayers, exchange bias (He) arises from the interfacial exchange coupling between the two layers and reflects the microscopic orientation of the antiferromagnet. Here the possibility of single-shot switching of the antiferromagnet (change of the sign and amplitude of He) with a single femtosecond laser pulse in IrMn/CoGd bilayers is demonstrated. The manipulation is demonstrated in a wide range of fluences for different layer thicknesses and compositions. Atomistic simulations predict ultrafast switching and recovery of the AFM magnetization on a timescale of 2 ps. The results provide the fastest and the most energy-efficient method to set the exchange bias and pave the way to potential applications for ultrafast spintronic devices.

Electrical and Magnetic Properties of Materials for Electromagnetic Interference

General aspects about electromagnetic interference (EMI) have shown that various electronic and electrical devices, in the field of communications are very sensitive to many sources (emissions) of external electromagnetic waves with various bands of frequency components. All electrical equipment using radio communication contains intentional emitters and sensitive receivers. Since electrical and magnetic materials have different properties, the objective of this paper is to explore the shielding effectiveness of some materials and to suggest new compounds that satisfies the effective shielding requirements.

Van der Waals Heterostructures for Photoelectric, Memory, and Neural Network Applications

A van der Waals (vdW) heterostructure is formed by combining multiple materials through vdW bonds. It can combine the advantages of electronic, optical, thermal, and magnetic properties of different 2D materials and has the potential to develop into the next generation of high‐performance functional devices. Herein, the current research advances of vdW heterostructures are reviewed. First, current fabrication methods and physical structures of vdW heterostructures are summarized. The 2D/nD (n = 0,1,2,3) mixed‐dimensional heterostructures are discussed in detail. Second, a new type of vdW heterostructure is introduced based on two‐dimensional electron gas with a nanoscale junction interface. Finally, the application prospects of vdW heterostructures in photoelectric and memory devices are further outlined by combing new applications in the neural networks. This review shows that vdW heterostructures have great advantages in high integration, energy harvesting, and logical operations, and it provides directions and suggestions for the future research and application of environmentally friendly, high‐performance, and smart functional devices.

Magnetic Domain Wall Networked Films – Configurational Switching for Tunable Magnetization Dynamics by Perforated Thin Films

AbstractSetting the magnetization and its properties in magnetic materials and films is of the utmost fundamental and technological importance for magnetic applications and devices. Magnetic permeabilities in a material are generally defined by the acting magnetic anisotropies together with an applied magnetic field. Here, deterministic switching of the effective dynamic magnetic properties is demonstrated by tunable networks of magnetic domain walls. By perforating magnetic films, a reversible switching between different magnetization states is achieved. Due to the resulting local effective dynamic fields for the changed domain configurations, different zero‐field permeability spectra are attained for the same material structure. Using local configurational magnetic resonances confined by magnetic domain walls, deterministic switchable bimodal dynamic behavior is achieved. Dynamic magnetooptical Kerr microscopy with picosecond temporal resolution proves that the varying periodic magnetic domain configurations are responsible for the dynamic magnetic bistability. In particular, the field‐free precessional magnetic response can be reproducibly switched between 1.3 and 2.3 GHz. The magnetization dynamics can be modified by small interventions in a repeatable manner beyond fixed material and structural properties. The described fundamental mechanism enables to design new energy efficient configurational microwave devices by switching between zero‐field magnetic arrangements.