Magnetostrictive Plate Research Articles

Magnetoelectric properties in Ni/Pb(Zr,Ti)O3/FeCo laminated composites with different extensional strain modes

Magnetoelectric (ME) Ni/ Pb(Zr,Ti)O3 (PZT)/ FeCo laminated composites were made up of negative magnetostrictive/piezoelectric/positive magnetostrictive plates, in which negative and positive magnetostrictive plates were bonded on the piezoelectric plates with different orders to obtain three different extensional strain modes: (i) bending extensional strain (BES), (ii) longitudinal extensional strain (LES), and (iii) torsional extensional strain (TES). In the TES mode, ME voltage coefficients of 3.97 and 4.23V/cmOe were obtained at the bending and longitudinal resonance frequencies, respectively, which are much larger than those in the other two modes. All the experimental values of resonance frequencies in 1–160kHz range agree well with the calculated ones.

Giant self-biased converse magnetoelectric effect in multiferroic heterostructure with single-phase magnetostrictive materials

Giant self-biased converse magnetoelectric (CME) effects with obvious hysteretic behaviors are systematically investigated in two-phase SmFe2/PZT [Pb(Zr1−x, Tix)O3] multiferroic laminates at room temperature. Taking advantage of the huge anisotropic field of SmFe2 plate, large remnant CME coupling is provoked by this field instead of permanent magnets to bias the laminate. Consequently, bitable magnetization status switching is realized through a smaller ac voltage far below the electric coercive field in the absence of magnetic bias field. Experiments demonstrate that a large remnant CME coefficient (αCME) of 0.007 mG/V is achieved, exhibiting ∼50 times higher CME coefficient than the previous laminate composite multi-phase magnetostrictive plates. These results provide promising applications for realization of high-density magnetoelectric random access memories (MERAMs) devices with lower energy consumption.

Nonlinear dynamic characteristics and optimal control of a giant magnetostrictive film-shaped memory alloy composite plate subjected to in-plane stochastic excitation

The nonlinear dynamic characteristics and optimal control of a giant magnetostrictive film (GMF)-shaped memory alloy (SMA) composite plate subjected to in-plane stochastic excitation are studied. GMF is prepared based on an SMA plate, and combined into a GMF—SMA composite plate. The Van der Pol item is improved to explain the hysteretic phenomena of GMF and SMA, and the nonlinear dynamics model of a GMF—SMA composite cantilever plate subjected to in-plane stochastic excitation is developed. The stochastic stability of the system is analyzed, and the steady-state probability density function of the dynamic response of the system is obtained. The condition of stochastic Hopf bifurcation is discussed, the reliability function of the system is provided, and then the probability density of the first-passage time is given. Finally, the stochastic optimal control strategy is proposed by the stochastic dynamic programming method. Numerical simulation shows that the stability of the trivial solution varies with bifurcation parameters, and stochastic Hopf bifurcation appears in the process; the system's reliability is improved through stochastic optimal control, and the first-passage time is delayed. A GMF—SMA composite plate combines the advantages of GMF and SMA, and can reduce vibration through passive control and active control effectively. The results are helpful for the engineering applications of GMF—SMA composite plates.

Stochastic bifurcation and fractal and chaos control of a giant magnetostrictive film-shape memory alloy composite cantilever plate subjected to in-plane harmonic and stochastic excitation

Stochastic bifurcation and fractal and chaos control of a giant magnetostrictive film–shape memory alloy (GMF–SMA) composite cantilever plate subjected to in-plane harmonic and stochastic excitation were studied. Van der Pol items were improved to interpret the hysteretic phenomena of both GMF and SMA, and the nonlinear dynamic model of a GMF–SMA composite cantilever plate subjected to in-plane harmonic and stochastic excitation was developed. The probability density function of the dynamic response of the system was obtained, and the conditions of stochastic Hopf bifurcation were analyzed. The conditions of noise-induced chaotic response were obtained in the stochastic Melnikov integral method, and the fractal boundary of the safe basin of the system was provided. Finally, the chaos control strategy was proposed in the stochastic dynamic programming method. Numerical simulation shows that stochastic Hopf bifurcation and chaos appear in the parameter variation process. The boundary of the safe basin of the system has fractal characteristics, and its area decreases when the noise intensifies. The system reliability was improved through stochastic optimal control, and the safe basin area of the system increased.

Magnetoelectric properties and magnetomechanical energy harvesting from stray vibration and electromagnetic wave by Pb(Mg1/3Nb2/3)O3-Pb(Zr,Ti)O3 single crystal/Ni cantilever

Magnetoelectric (ME) rectangular unimorph cantilever beam structures of piezoelectric Pb(Mg1/3Nb2/3)O3-Pb(Zr,Ti)O3 (PMN-PZT) single crystal on magnetostrictive Ni plate was designed with ⟨001⟩ and ⟨011⟩-cut crystallographic directions and investigated their ME response and mechanical vibration based energy harvesting behavior. Both magnetoelectric (ME) voltage coefficient (αME) and mechanically harvested power output was found to be strongly dependent on the crystallographic cut directions of PMN-PZT single crystals. The maximum αME and power output of 7.28 V/cm Oe and 1.31 mW was observed for ⟨011⟩ PMN-PZT/i unimorph ME structure at resonance mode under 0.7 G acceleration. The ⟨011⟩ PMN-PZT single crystal showed that in-plane anisotropic behavior, i.e., d31 and d32 significantly affect to the magnitude of αME and harvested power output.

Enhanced magneto-impedance in Fe73.5Cu1Nb3Si13.5B9 ribbons from laminating with magnetostrictive terfenol-D alloy plate

The authors report an amplified magneto-impedance (MI) in a laminated composite composed of a magnetostrictive terfenol-D plate and a Fe73.5Cu1Nb3Si13.5B9 ribbon that exhibits an intrinsic MI. When a dc magnetic field is applied to a laminated composite, the magnetostriction from the terfenol-D plate induces a giant stress that is simultaneously transferred to the ribbon, generating a stress-induced impedance (SI). Combining the terfenol-D magnetostriction and the SI of the ribbon produces an enhanced MI. The maximum MI ratio for the composite is ∼74%, which is ∼27 times higher than that for a single ribbon.

Transient Response of Magnetostrictive Functionally Graded Material Square Plates Under Rapid Heating

AbstractWe used the generalized differential quadrature (GDQ) method to compute the transient responses of thermal stresses and center deflection amplitude in the magnetostrictive functionally graded material (FGM) square plate under rapid heating acting at its lower surface. We obtained the GDQ solutions in the three-layer of magnetostrictive FGM plates subjected to four simply supported edges. We presented the transient responses of thermal stress and center deflection amplitude of magnetostrictive FGM plates with/without velocity feedback control, respectively, under the effects of the ratio of length to thickness, the power law index, the temperature of environment and the applied heat flux.

Rapid Heating Induced Vibration of Magnetostrictive Functionally Graded Material Plates

The thermal vibration study of magnetostrictive functionally graded material (FGM) plate under rapid heating is computed by using the generalized differential quadrature (GDQ) method. The dynamic equilibrium differential equations with displacements and shear rotations of magnetostrictive FGM plate under the rapid heating are normalized and discretized into the dynamic discretized equations. The computational solutions of magnetostrictive FGM plate with four simply supported edges are obtained. Some parametric effects on the magnetostrictive FGM plates are analyzed, they are: thickness of mounted magnetostrictive layer, control gains of the proportional negative derivative, rapid heating flux values, and power law index values of FGM plate.

J044105 磁歪材料を用いた振動物体からのエネルギーハーベスト

Up to the present, by using the Terfenol-D (Tb-Dy-Fe alloy from ONR/USA) giant magnetostrictive alloys containing rare earth elements, there was an example of measuring power generation due to vibration of the impact force and compression force of the uniaxial direction. Terfenol-D has been limited field of application because it is brittle but high cost. In this study, we investigated the characteristics of the vibration generator when two magnetostrictive alloys of magnetostrictive FeCo-and FeGa, in that way, the inverse magnetostrictive effect of magnetostrictive material is used, and the beam is vibrated and paste the magnetostrictive material plate to the cantilever. A leakage flux is generated by the inverse magnetostrictive effect distortion due to vibration, so that the induced currents generated by the change in magnetic flux of time were compared for each material. So, in addition, we also measured and compared the amount of magnetostriction and magnetization characteristics. As a result, important finding that applied stress and the amount of magnetostriction are strongly related with the output voltage of the magnetostrictive vibration generator.

Theory of magnetoelectric effect in laminate composites considering two-dimensional internal stresses and equivalent circuit

By taking into account the transverse stresses produced in both the transversely poled piezoelectric plate and the longitudinally magnetized magnetostrictive plate, we develop an 2D stresses magnetoelectric (ME) effect theoretical model. The ME voltage expressions are given by combing constitutive equations and equation of motion for the ME element, accompanied by boundary conditions and charge source equivalent circuit. Theoretical results show the detailed relationships among ME voltage coefficient, geometric parameters, and physical parameters of the composites, as well as the circuit parameters. Compared with 1D stresses theory, the 2D stresses theoretical results are in better agreement with the experimental data.

Demagnetizing factors for two parallel ferromagnetic plates and their applications to magnetoelectric laminated sensors

An analytical expression is derived to approximate the magnetometric demagnetizing factors for two parallel ferromagnetic plates having the shape of rectangular prisms. The magnetometric demagnetizing factors relate the average magnetic fields within the plates’ volumes to an external magnetic field. Knowing this relationship is essential for describing the response of magnetoelectric sensors comprising two parallel magnetostrictive plates. It is shown that two separate ferromagnetic layers provide better field sensitivity than a single layer with a doubled thickness. The obtained results are in a good agreement with numerical calculations and experimental data.

Multimodal Vibration Harvester Using Inductive and Magnetostrictive Mechanisms

Multimodal energy harvester comprising of magnetostrictive and electromagnetic system was designed and analyzed with overall shape and size similar to AA battery. In the proposed design, magnetostrictive plates were mounted on the base and top cap of the harvester. The cylindrical shell housed a magnetic levitation cavity where center magnet was suspended between the top and bottom magnet attached to the base and top cover. This design allows the system to harvest energy from magnetostrictive material through Villari effect and from the oscillating permanent magnet within a hollow cavity through Faraday's effect. By specifying generator geometry and estimating system parameters, theoretical output power for the proposed design was determined for two different center magnet geometry. The output power and voltage was analyzed using the analytical and FEM modeling to identify the overall response of the multimodal structure.

Transient responses of magnetostrictive plates by using the GDQ method

Abstract We used the generalized differential quadrature (GDQ) method to compute the transient response of thermal stresses and center displacement in laminated magnetostrictive plates under thermal vibration. We obtained the GDQ solutions in a three-layer (0° m /90°/0) and a 10-layer (0° m /90°/0°/90°/0) s laminated magnetostrictive plate with four simply supported edges. We presented the transient responses of thermal stress and center displacement with and without velocity feedback control, respectively. The advantage of the GDQ method used provide us with an efficient method to compute the results including shear deformation effect with a few grid points. These GDQ results had its potential that could be used and considered as basic data in the future magnetostrictive laminate studies.

A magnetoelectric energy harvester and management circuit for wireless sensor network

This paper presents an electromagnetic energy harvesting scheme by using a composite magnetoelectric (ME) transducer and a power management circuit. In the transducer, the vibrating wave induced from the magnetostrictive Terfenol-D plate in dynamic magnetic field is converged by using an ultrasonic horn. Consequently more vibrating energy can be converted into electricity by the piezoelectric element. A switching capacitor network for storing electricity is developed. The output of the transducer charges the storage capacitors in parallel until the voltage across the capacitors arrives at the threshold, and then the capacitors are automatically switched to being in series. More capacitors can be employed in the capacitor network to further raise the output voltage in discharging. For the weak magnetic field environment, an active magnetic generator and a magnetic coil antenna under ground are used for producing an ac magnetic field of 0.2–1 Oe at a distance of 25–50 m. In combination with the supply management circuit, the electromagnetic energy harvester with a rather weak power output (about 20 μW) under an ac magnetic field of 1 Oe can supply power for wireless sensor nodes with power consumption of 75 mW at a duration of 620 ms.

Magnetoelectric effect in laminates of polymer-based pseudo-1–3 (Tb0.3Dy0.7)0.5Pr0.5Fe1.55 composite and 0.3Pb(Mg1/3Nb2/3)O3–0.7PbTiO3 single crystal

We report an extrinsic magnetoelectric effect in composite laminates made by sandwiching one thickness-polarized 0.7Pb(Mg(1/3)Nb(2/3))O(3)-0.3PbTiO(3) (PMN-PT) piezoelectric single crystal plate between two length-magnetized, polymer-based pseudo-1-3 (Tb(0.3)Dy(0.7))(0.5)Pr(0.5)Fe(1.55) magnetostrictive composite plates. The laminates exhibit large magnetoelectric voltage coefficients (alpha (V) ) of similar to 0.17 V/Oe with a flat response for frequencies in excess of 40 kHz and of similar to 2.97 V/Oe at the natural resonance frequency of similar to 65 kHz. The distinct advantages of the laminates include high magnetic field sensitivity, low Joule heating loss, wide operating bandwidth, and low cost.

Transient responses of magnetostrictive plates without shear effects

The generalized differential quadrature (GDQ) method was used to compute the transient response of laminated magnetostrictive plate under thermal vibration. The GDQ solutions were obtained for the three-layer (0° m /90°/0°) of laminated magnetostrictive plates under four simply supported edges. The transient responses of thermal stresses and center displacement with and without shear effect were presented, respectively in the thin and thick plate.

Giant sharp converse magnetoelectric effect from the combination of a piezoelectric transformer with a piezoelectric/magnetostrictive laminated composite

Giant sharp converse magnetoelectric (CME) coefficient of 11.9G∕V is obtained in a heterostructure formed by combining a Rosen-type 0.7Pb(Mg1∕3Nb2∕3)O3–0.3PbTiO3 (PMN-PT) piezoelectric single-crystal transformer with a CME laminated composite of a length-magnetized Tb0.3Dy0.7Fe1.92 (Terfenol-D) magnetostrictive alloy plate sandwiched between two thickness-polarized, electroparallel-connected PMN-PT piezoelectric single-crystal plates. The observed giant sharp CME is found to originate from the step-up voltage-gain effect in the transformer and the resonance CME effect in the laminated composite. This heterostructure has promising applications in electrically controlled magnetic memory devices.

Magnetoelectric effect in a parallel sandwich of magnetostrictive pseudo-1–3 composite and piezoelectric 2–2 composite

A two-phase magnetoelectric (ME) parallel sandwich was developed by bonding two longitudinally magnetized Terfenol-D/epoxy pseudo-1–3 magnetostrictive composite plates on two longitudinally polarized PZT/epoxy 2–2 piezoelectric composite plates combined longitudinally as a single plate and with their polarization directions arranged in reverse directions. A significantly large ME voltage sensitivity (ME V ) of 3.1 V/Oe was observed at the resonance frequency of 42.8 kHz under a relatively low bias field of 0.8 kOe. This resonance ME V was ∼35 times larger than its nonresonance values, showing great promise of using the proposed sandwich in ME conversion devices.

Temperature compensation for a fiber‐Bragg‐grating‐based magnetostrictive sensor

AbstractWe demonstrate two simple techniques for the compensation of the temperature effects in a fiber‐Bragg‐grating‐based magnetostrictive sensor. These techniques are based on using two specially mounted fiber Bragg gratings (FBGs). In one technique, the two FBGs, perpendicular to each other, are bonded onto a single magnetostrictive plate, while in the other technique, they are bonded onto two different magnetostrictive bars that possess close thermal expansion coefficients and magnetostrictive coefficients of opposite signs. In both cases, the Bragg wavelength difference between the two FBGs is insensitive to the temperature and measures the sum of the magnetostrictive effects experienced by the two gratings. Using these techniques, we have been able to reduce the temperature sensitivity of the sensor by more than 10 times. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 36: 211–213, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10722

Mechanical Aging Behavior of Pb(Zn 1/3 Nb 2/3 )O 3 -PbTiO 3 and Pb(Mg 1/3 Nb 2/3 )O 3 -PbTiO 3 Single Crystals

Single crystals of complex lead perovskite have attained great importance in recent times due to their exceptionally high piezoelectric and electromechanical constants. The application of these materials in practical devices will to a large extent depend on the aging and fatigue characteristics of these crystals. With this aim, the aging characteristics of <001>-oriented Pb(Zn 1/3 Nb 2/3 )O 3 -PbTiO 3 (PZN-PT) and Pb(Mg 1/3 Nb 2/3 )O 3 -PbTiO 3 (PMN-PT) single crystals have been studied under electrical and mechanical drive. Under continuous bipolar drive, a significant increment in the magnitude of hysteretic loss and decrement in the piezoelectric constant was observed. Subsequently, a novel experimental setup was fabricated to characterize the mechanical fatigue behavior of the piezo-single crystals. In this method, the crystals are placed between the two magnetostrictive plates and clamped. The cyclic mechanical stress is applied using strong magnetic fields. It was found that the piezoelectric constants decreased slowly at both short and long times but there is a pronounced decrement at intermediate times. This behavior is detrimental in designing reliable devices. The aging behavior of the piezocrystals improved significantly by doping. This improvement is suggested to be due to the restriction of relaxation processes and ordering of the system.