Magnetostriction Research Articles

Magnetostriction Effect on Vibration and Acoustic Noise in Switched Reluctance Motor

Magnetostriction Effect on Vibration and Acoustic Noise in Switched Reluctance Motor

Magnetism-structure triple point morphotropic phase boundary and resulting W-type magnetostrictive effect in Ni50Mn34Sb16−xGax Heusler alloys

Magnetism-structure triple point morphotropic phase boundary and resulting W-type magnetostrictive effect in Ni50Mn34Sb16−xGax Heusler alloys

Study on the microstructure and wear resistance of Fe-Co-Sm alloy coatings with different Sm contents assisted by alternating magnetic field during laser cladding

This study employs a 20 mT alternating magnetic field-assisted laser cladding technique to fabricate high wear-resistant Fe-Co alloy coatings with varying Sm content on a 42CrMo substrate. The research investigates the changes in lattice constants and magnetostrictive effects in paramagnetic materials under the influence of an alternating magnetic field. Different Sm content coatings were characterized in terms of their micro-structure and phase composition. Measurements were taken for the hardness and elastic modulus of the coating surface, and friction and wear tests were conducted. It was found that a minor addition of Sm enhances the magnetic properties of Fe-Co-based materials, leading to a stronger magnetostrictive effect. Furthermore, the grain structure of the cladding layer is significantly refined, the eutectic regions between dendrites are reduced, and the hardness and wear resistance of the coating are markedly improved. With a composition of 1.2 wt% Sm, the coating showed the greatest microhardness and elastic modulus, and its wear resistance increased by 45.6 % compared to the original coating. With increasing Sm content, the wear resistance of the coating initially increases and then decreases. The combined application of the alternating magnetic field and the addition of rare earth element Sm significantly enhances the overall performance of the Fe-Co alloy coating.

A Contactless Low-Carbon Steel Magnetostrictive Torquemeter: Numerical Analysis and Experimental Validation.

Torque measurement is a key task in several mechanical and structural engineering applications. Most commercial torquemeters require the shaft to be interrupted to place the sensors between the two portions of the shaft where a torque has to be measured. Contactless torquemeters based on the inverse magnetostrictive effect represent an effective alternative to conventional ones. Most known ferromagnetic materials have an inverse magnetostrictive behavior: applied stresses induce variations in their magnetic properties. This paper investigates the possibility of measuring torsional loads applied to a shaft made of ferromagnetic steel S235 through an inverse magnetostrictive torquemeter. It consists of an excitation coil that produces a time-varying electromagnetic field inside the shaft and an array of sensing coils suitably arranged around it, in which voltages are induced. First, the system is analyzed both in unloaded and loaded conditions by a Finite Element Method, investigating the influence of relative positions between the sensor and the shaft. Then, the numerical results are compared with the experimental measurements, confirming a linear characteristic of the sensor (sensitivity about 0.013 mV/Nm for the adopted experimental setup) and revealing the consistency of the model used. Since the system exploits the physical behavior of a large class of structural steel and does not require the introduction of special materials, this torquemeter may represent a reliable, economical, and easy-to-install device.

Peculiarities of Hysteretic Properties and Magnetostriction of Nano-Structured Fe10Ni90 Films

The study is related to the investigation of hysteresis and magnetostrictive properties of single-layer Fe10Ni90 films and nano-structured [Fe10Ni90/Cu]p/Fe10Ni90 films, where the magnetostrictive layers are separated with a nonmagnetic interlayer. The magnetostriction effect is shown to depend on the total layer thickness; in this case, the magnetostriction of the [Fe10Ni90/Cu]p/Fe10Ni90 film structures was found to be higher than that of the single-layer Fe10Ni90 films. The observed peculiarity is associated with weakening the fixing effect of a substrate.

Combining Magnetostriction with Variable Reluctance for Energy Harvesting at Low Frequency Vibrations

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.

Spin-Mechanical Coupling in 2D Antiferromagnet CrSBr.

Spin-mechanical coupling is vital in diverse fields including spintronics, sensing, and quantum transduction. Two-dimensional (2D) magnetic materials provide a unique platform for investigating spin-mechanical coupling, attributed to their mechanical flexibility and novel spin orderings. However, studying their spin-mechanical coupling presents challenges in probing mechanical deformation and thermodynamic property changes at the nanoscale. Here we use nano-optoelectromechanical interferometry to mechanically detect the phase transition and magnetostriction effect in multilayer CrSBr, an air-stable antiferromagnet with large magnon-exciton coupling. The transitions among antiferromagnetism, spin-canted ferromagnetism, and paramagnetism are visualized. Nontrivial magnetostriction coefficient 2.3 × 10-5 and magnetoelastic coupling strength on the order of 106 J/m3 have been found. Moreover, we demonstrate the substantial tunability of the magnetoelastic constant by nearly 50% via gate-induced strain. Our findings demonstrate the strong spin-mechanical coupling in CrSBr and pave the way for developing sensitive magnetic sensing and efficient quantum transduction at the atomically thin limit.

A one-step fabrication method of flexible magnetostrictive fiber ribbon based on Fe50Co50 alloy and its characteristics study

Magnetostrictive materials are widely used in sensors, actuators and micro-nano electronics because of their excellent performance. However, traditional rigid magnetostrictive materials are difficult to adapt to the flexible and deformable structure of flexible electronic devices. In order to solve the deformation, sensing and control problems in the field of flexible electronics, a one-step new method of is proposed to deposit Fe50Co50 fiber ribbons with reciprocated and loop structures on flexible substrate. Helmholtz coil is designed to test the magnetostrictive positive effect ability of Fe50Co50 ribbon, and its magnetostrictive strain curve is analyzed. Furthermore, frequency domain characteristics of Fe50Co50 ribbon are tested, and the influence of externally driving magnetic field on elastic layer materials and resonance output characteristics is analyzed. The experimental results show that Fe50Co50 ribbon exhibits good low-frequency magnetic field characteristics. And free end displacement of Fe50Co50 ribbon based on loop structure, under 12 mT alternating magnetic field and 134 mT bias magnetic field, reaches a peak-to-peak value of 870 μm for first-order resonance, and 320 μm for second-order resonance. This verifies that Fe50Co50 ribbon possesses the expected properties that magnetostrictive materials should have, and innovatively breaks through the technical bottleneck of manufacturing flexible micro-nano magnetostrictive energy exchange components.

Observation of the multiple magnetic phases in double perovskite Pr1.8La0.2CoFeO6

The structural and magnetic properties of the double perovskite Pr1.8La0.2CoFeO6 have been investigated. The X-ray diffraction study shows that the system acquires room-temperature orthorhombic phase with the Pnma space group. The X-ray photoemission spectroscopy (XPS) measurement confirmed that the B-site ions are present in mixed valence states i.e. Co has been found in Co2+ and Co3+ valance states whereas Fe has been found in Fe3+/Fe4+. Magnetic measurements of the system confirm the existence of several fascinating magnetic behaviors, such as long-range canted antiferromagnetism withTN ∼ 271 K, giant exchange bias, and re-entrant cluster glass phase (TG ∼ 33 K). Field-dependent magnetization shows a large spontaneous exchange bias; HSEB∼ 1.8 kOe and giant conventional exchange bias, HCEB∼ 2.4 kOe at 5 K. Antiferromagnetic materials with large exchange bias can be utilized in high-density spintronic devices. Temperature-dependent Raman study demonstrates that the observed phonon mode exhibits anomalous behavior close to the magnetic transition temperature. Analysis of anomalous softening of phonon mode below TN, clarifies the presence of significant spin-phonon coupling while the magnetostriction effect does not play any significant role in the observed phonon anomaly.

Microwave frequency combs through the rotational enhanced magnetostrictive effect

Microwave frequency combs through the rotational enhanced magnetostrictive effect

Effects of boron on microstructure, wear and corrosion properties of external magnetic field assisted laser metal deposition coatings

Coatings with different boron content were prepared by magnetic field-assisted Co-based laser metal deposition on 300 M ultra-high strength steel. The effects of boron content on the magnetic properties, mechanical properties, friction and wear properties, and corrosion resistance of the coating were investigated. The research results indicate that adding 6 wt% of boron to cobalt alloy in a 35 mT alternating magnetic field is beneficial for refining the microstructure, which can improve the mechanical properties of the coating. This research also discusses the effect of boron content on the wear and corrosion resistance of the coating. The results show that adding boron content enhances the magnetostrictive effect, and reduces the elastic modulus of the laser metal deposition coating while ensuring its hardness, thereby improving the wear and corrosion resistance of the laser metal deposition layer. The hardness of the coating can reach 1215 HV. The friction coefficient and corrosion current density of the coating are reduced by 26.9% and 60.2% respectively compared with the substrate. This work can help promote the application of laser metal deposition technology, reduce costs, and ensure performance.

Design optimization of two-dimensional wireless passive force sensor based on finite element analysis

Abstract A two-dimensional wireless and passive sensor based on finite element analysis (FEA) is designed, analyzed, optimized, and tested. The sensor is using the inverse magnetostrictive effect. The sensor included three pieces of sensitive elements that stick to the sensitive area of the elastomer. The FEA mothed is used to assist the design, analysis, and optimization process. The strain-sensitive area of the tension and torque are located in different areas, according to the finite element analysis. When the sensor was fabricated, the sensor’s output performance was tested. The experiment results show that the effective range of tension is 40 N, and the effective range of torque is 4 N·m. The optimized smart structure has a good decoupling effect, which can reduce coupling between dimensions. Finally, the two-dimensional force information can be detected passively and wirelessly.

Modulated magnetostriction and multiferroic properties in the PVDF-based cobalt ferrite particulate composites

Multiferroic materials (MFM) have drawn substantial attention for developing smart magnetodielectric devices. Herein, cobalt ferrite CoFe2O4 (CFO) was synthesized by a glycine–nitrate sol-gel auto-combustion route and, PVDF-based particulate composite films embedded with CFO have been developed. A comprehensive investigation evaluated the effects of magnetostriction, initiated from the embedded CFO phase, on magnetodielectric characteristics of composite films. The structural, electrical, magnetostrictive and magnetodielectric properties were investigated. The embedded CFO particulate endows PVDF matrix at a higher β–phase forming ability, which enhances the ferroelectricity with a polarisation (Pmax∼1.09 μC/cm2@ 850 kV/cm), a higher dielectric constant (εr∼12.33) and lower dielectric loss. The typical magnetic hysteresis loop was obtained with saturation magnetization (MS∼4.96 emu/g) and coercivity (HC∼1.49 kOe), revealing the ferromagnetic ordering in composite films. The response of the magnetodielectric (MD) is observed at room temperature, that is, a large negative MD coefficient ∼2.1 % @ Hcr∼5.0 kOe is achieved for Co0.9Fe2.1O4/PVDF composite films, while MD∼0.65 %@ Hcr∼1.0 kOe is obtained for Co1.1Fe1.9O4/PVDF films, accompanied by a maximum MD∼4.35 % at resonance frequency. The variation in the MD performance reveals a close correlation to the modulated magnetostriction, such as the magnetocrystalline anisotropy, field-induced coefficient and magnetostrictive susceptibility, indicating the strain-mediated coupling MD effect. The multiferroic properties in CoxFe3–xO4/PVDF composites have potential for magneto-dielectric sensing applications. Furthermore, this work would be exploited to understand MD coupling mechanism and develop MFM for multifunctional devices.

Direct and inverse magnetocaloric effects in magnetostrictive GdMn2Ge2 with field-induced metamagnetic transition

Heavy rare-earth-based ternary intermetallic compounds with the formula RT2X2 have drawn great interest because of their multiple magnetic transitions and various magnetic structures. Here, anisotropic magnetic behaviors, magnetocaloric effects (MCEs), and magnetostriction effects in single-crystalline GdMn2Ge2 are studied in two different directions. Experiments show a magnetic transition characterized by a sudden decrease in magnetization for μ0H//a and a sharp increase for μ0H//c at Tt. The transition is driven by lower temperatures for μ0H//a, contrasting that for μ0H//c with an increase in the magnetic field. An inverse MCE is observed for μ0H//a with a maximum magnetic entropy change (−ΔSMmax) of −7.4 J kg−1 K−1 (μ0ΔH = 6 T), while a direct MCE is obtained for μ0H//c with an −ΔSMmax of 8.0 J kg−1 K−1 under the same magnetic field change. Moreover, a remarkable field-induced metamagnetic transition and a magnetostriction effect are observed simultaneously at Tt, indicating strong magneto-lattice coupling. The T-μ0H phase diagrams are constructed based on the magnetic properties. The coexistence of direct and inverse MCEs is discussed and is due to the spin-flop of Mn and anisotropic magnetic properties under magnetic fields in different directions.

Investigation of Lithium-Ion Battery Performance Utilizing Magnetic Controllable Superionic Conductor Li3(V1-x Fe x )2(PO4)3/C (x = 0.05 and 0.10).

Lithium-ion batteries with Li3V2(PO4)3/C as the cathode have been a popular research topic in recent years; however, studies of the effects of external magnetic fields on them are less common. This study investigates the effects of an external magnetic field applied parallel to the direction of the anode and cathode on the ion transport through iron-doped Li3(V1-x Fe x )2(PO4)3, the outer carbon coating, the film/electrolyte/separator, and up to the lithium metal electrode on a microscopic level. The results reveal that for the x = 0.05 sample with lower doping, the magnetostriction expansion of Li3(V1-x Fe x )2(PO4)3 and the magnetostrictive contraction effect of the outer ordered carbon layer cancel each other out, resulting in no significant enhancement of the battery's energy and power density due to the external magnetic field. In contrast, the x = 0.1 sample, lacking magnetostrictive contraction in the outer ordered carbon layer, shows that its energy and power density can be influenced by the magnetic field. Under zero magnetic field, the cyclic performance exhibits superior average capacity performance in the x = 0.05 sample, while the x = 0.1 sample shows a lower decay rate. Both samples are affected by the magnetic field; however, the x = 0.1 sample performs better under magnetic conditions. In particular, in the C-rate tests under a magnetic field, the sample with x = 0.1 showed a significant relative reduction in capacity decay rate by 20.18% compared to the sample with x = 0.05.

Compositional dependence of magnetostrictive effect in Ta/CoFe(B)/MgO stacks with perpendicular magnetic anisotropy

Magnetostrictive effect in Ta/Co x Fe100−x (B)[CoFe(B)]/MgO for alloy compositions spanning Fe-rich (x = 20) to Co-rich (x = 80) stacks has been studied to investigate the relation between magnetostrictive effect and the onset of perpendicular magnetic anisotropy at Ta/CoFe(B)/MgO interfaces. Interestingly, for each Co composition, a t-dependent crossover between in-plane (ip) and out-of-plane (op) magnetic anisotropy is found at a different CoFe(B) thickness (t cro)–denoted as crossover thickness, which means compositional variations of magnetic properties at the interfaces. By considering the Ta/CoFe(B) and CoFe(B)/MgO interfaces as atomistic volumes with ip and op orbital magnetizations, respectively, the relative ratio of ip to op orbital magnetization in the atomistic volumes is found to be closely related to the dependence of magnetostriction constant (λ s) on the Co composition. The findings suggest that the composition dependence of ip and op orbital magnetization at the Ta/CoFe(B)/MgO interfaces plays an important role in controlling its interfacial anisotropy and magnetostrictive effect of the stacks with the interfaces.

Harnessing the Induced Magnetostrictive Effect in Fully Flexible Fiber-Based Magnetoelectric Composites for Improved Stray Magnetic Energy Harvesting

Harnessing the Induced Magnetostrictive Effect in Fully Flexible Fiber-Based Magnetoelectric Composites for Improved Stray Magnetic Energy Harvesting

Molecular ferroelectric with low-magnetic-field magnetoelectricity at room temperature

Magnetoelectric materials, which encompass coupled magnetic and electric polarizabilities within a single phase, hold great promises for magnetic controlled electronic components or electric-field controlled spintronics. However, the realization of ideal magnetoelectric materials remains tough due to the inborn competion between ferroelectricity and magnetism in both levels of symmetry and electronic structure. Herein, we introduce a methodology for constructing single phase paramagnetic ferroelectric molecule [TMCM][FeCl4], which shows low-magnetic-field magnetoelectricity at room temperature. By applying a low magnetic field (≤1 kOe), the halogen Cl‧‧‧Cl distance and the volume of [FeCl4]− anions could be manipulated. This structural change causes a characteristic magnetostriction hysteresis, resulting in a substantial deformation of ~10−4 along the a-axis under an in-plane magnetic field of 2 kOe. The magnetostrictive effect is further qualitatively simulated by density functional theory calculations. Furthermore, this mechanical deformation significantly dampens the ferroelectric polarization by directly influencing the overall dipole configuration. As a result, it induces a remarkable α31 component (~89 mV Oe−1 cm−1) of the magnetoelectric tensor. And the magnetoelectric coupling, characterized by the change of polarization, reaches ~12% under 40 kOe magnetic field. Our results exemplify a design methodology that enables the creation of room-temperature magnetoelectrics by leveraging the potent effects of magnetostriction.

Modeling and radiation performance analysis of acoustically actuated magnetoelectric antennas

Bulk acoustic wave-mediated magnetoelectric (ME) antenna is the most promising acoustically actuated ultra-compact antenna scheme at ultrahigh frequency (0.3–3 GHz). However, the relevant research is still exploratory, and the antenna’s multi-field coupling modeling and performance analysis are imperfect. This work presents a cellular model based on finite element simulation to analyze the radiation characteristics of the ME antenna integrated on a thin-film bulk wave resonator (FBAR). Compared with the finite difference time domain (FDTD) method, the cellular model has the advantages of simplicity and high universality. The effects of mechanical and dielectric losses of piezoelectric (PE) material and mechanical and eddy current losses of magnetostrictive (MS) material on radiation efficiency are analyzed through the intensive research of unit cells of four different material combinations. Results show that the mechanical quality factors and piezomagnetic stress constant are the key parameters to determine the radiation efficiency. Besides conductivity and permeability, eddy current loss is also closely related to the thickness of the MS layer. This study provides a theoretical foundation for enhancing the radiation performance of ME FBAR antennas and identifying areas for further development.

Phase-field modeling of fracture for ferromagnetic materials through Maxwell’s equation

Electro-active materials are classified as electrostrictive and piezoelectric materials. They deform under the action of an external electric field. Piezoelectric material, as a special class of active materials, can produce an internal electric field when subjected to mechanical stress or strain. In return, there is the converse piezoelectric response, which expresses the induction of the mechanical deformation in the material when it is subjected to the application of the electric field. This work presents a variational-based computational modeling approach for failure prediction of ferromagnetic materials. In order to solve this problem, a coupling between magnetostriction and mechanics is modeled, then the fracture mechanism in ferromagnetic materials is investigated. Furthermore, the failure mechanics of ferromagnetic materials under the magnetostrictive effects is studied based on a variational phase-field model of fracture. Phase-field fracture is numerically challenging since the energy functional may admit several local minima, imposing the global irreversibility of the fracture field and dependency of regularization parameters related discretization size. Here, the failure behavior of a magnetoelastic solid body is formulated based on the Helmholtz free energy function, in which the strain tensor, the magnetic induction vector, and the crack phase-field are introduced as state variables. This coupled formulation leads to a continuity equation for the magnetic vector potential through well-known Maxwell’s equations. Hence, the energetic crack driving force is governed by the coupled magneto-mechanical effects under the magneto-static state. Several numerical results substantiate our developments.