Thickness Of Magnetostrictive Layer Research Articles

Investigation of phonons and magnons in [Ni80Fe20/Au/Co/Au] N multilayers

The interaction between phonons and magnons is a rapidly developing area of research, particularly in the field of acoustic spintronics. To discuss this interaction, it is necessary to observe two different waves (acoustic and spin waves) with the same frequency and wavelength. In the Ni80Fe20/Au/Co/Au system deposited on a silicon substrate, we observe the interaction between spin waves and surface acoustic waves using Brillouin light scattering spectroscopy. As a result, we can selectively control (activate or deactivate) the magnetoelastic interaction between the fundamental spin wave mode and surface acoustic waves. This is achieved by adjusting the magnetostrictive layer thickness in the multilayer. We demonstrate that by adjusting the number of layers in a multilayer structure, it is possible to precisely control the dispersion of surface acoustic waves while having minimal impact on the fundamental spin wave mode.

Numerical interpretation and experimental investigation of enhanced magnetoelectric effect in Ni/PZT distributed disc structured composite

The enhanced applicability of multifunctional magnetoelectric (ME) composites require them to be highly sensitive, compact and stable which has led to the development of epoxy-free self-biased ME composites. Recently proposed novel distributed disc structured (DDS) ME composite configuration led to a significant increase in ME output by a consistent increment in the number of piezoelectric discs embedded in magnetostrictive phase. This article experimentally and numerically deciphers the physics associated with the enhanced performance of DDS ME composite configurations. The enhancement in compressive prestress and the ability of DDS composites to function as multi ME composite system when operated in series combination of PZTs have been shown to be the predominant reasons attributed to the increase in ME response over the traditional disc/ring structure. The dependence of ME output of DDS composites on their orientation in applied magnetic field has been studied and the optimum placement has been identified. Finite element modeling has been used to discern the mechanical and the magnetic attributes that influence the experimentally obtained ME response with respect to connection of PZTs, angle and thickness of magnetostrictive layer. Furthermore, the ME coupling factor in various DDS configurations has been shown to be inversely dependent on the circumferential interface length.

Hygrothermal vibration of a laminated sandwich plate with magnetostrictive faces and a homogeneous core

AbstractHygrothermal forced vibration and damping analyses of a simply supported symmetric laminated composite plate with homogeneous core and magnetostrictive layers are examined using the exponential displacement model in this article. Three hygrothermal environment distribution types are investigated: uniform, linear and nonlinear rises in the present analysis. The equations of motion for laminated rectangular plates subjected to hygrothermal loads and in‐plane forces in x and y directions are developed through Hamilton's principle. The closed‐form solution is arrived at based on Navier's technique to analyze the hygrothermal effect on the vibrational behavior of the structure. Some parametric examples are presented to discuss the effects of the smart layer location, lamination schemes, mode number, aspect ratio, thickness ratio, feedback gain control value, in‐plane forces, core thickness‐to‐fiber reinforced layer thickness ratio, magnetostrictive layer thickness to fiber‐reinforced layer thickness ratio, temperature and moisture changes on vibration response of the proposed model. The study results illustrate that the high hygro ratio weakens the plate stiffness, and accordingly, the amplitude of the deflection increases with raising the moisture and/or temperature. The numerical results emphasize the strong role of the feedback control gain values and the smart layer position in controlling the system vibration. The largest deflections and highest damping time interval happen in the uniform temperature distribution and moisture concentration case. Moreover, the vibration frequencies of the thin smart plates are smaller than the thick ones.

Thermal vibration of magnetostrictive functionally graded material shells by considering the varied effects of shear correction coefficient

Abstract This paper investigates the thermal vibration of magnetostrictive functionally graded material (FGM) cylindrical shells by using the generalized differential quadrature (GDQ) method based on the first-order shear deformation theory (FSDT). The varied effects of shear correction coefficient are employed and obtained by using the total strain energy principle. The computed and varied values of shear correction coefficient are usually functions of magnetostrictive layer thickness, FGM power law index and environment temperature. In the thermo-elastic stress–strain relations, the simpler form stiffness of FGM shells and the effect of the magnetostrictive coupling terms with velocity feedback control under linear temperature rise are considered. The effects of magnetostrictive layer thickness, control gain values, environment temperature and FGM power law index on the thermal vibration of magnetostrictive FGM thick cylindrical shells are obtained and analyzed.

A Mechanism for the Crossing of Orthogonal Magnetic Wires in Multiferroic Nanomagnet Logic

We report time division multiplexing-based seven-phase clocking mechanism for the crossing of magnetic wires by in-plane multiferroic nanomagnet logic (m-NML). By reasonably setting hold time and sequence of applied stress (or voltage), the proposed multiferroic clocking ensures correct signal propagation of two orthogonal m-NML wires (or paths). The effects of magnetostrictive layer thickness on required seven-phase clock period and strain are investigated. Accordingly, a link scheme between early four-phase clocking and proposed seven-phase multiferroic clocking is developed by compressing seven-phase clock period. Thus, exact computation synchronization and pipelining in the entire NML circuit have been implemented. Finally, power consumption in the proposed m-NML crossing is discussed. The result shows that the m-NML signal crossing can be achieved with an energy dissipation of only about 533 aJ.

Theory of frequency response of magnetoelectric effects in radially polarized thin cylindrical composites

A theoretical model for the frequency response of magnetoelectric (ME) effect in thin cylindrical piezoelectric-magnetostrictive composites is presented by using constitutive and elastodynamic equations. The calculated results show that there is a resonant enhancement peak of ME voltage coefficient in the electromechanical resonance region and the ME voltage coefficient at resonance frequency exceeds that at low frequency by one or two orders of magnitude. The resonance frequency is predicted to increase with decreasing average diameter D$ \bar{D}$ and increasing thickness of magnetostrictive layer t M of the cylindrical composite, which is in good agreement with the experimental results reported in literatures. The corresponding resonance ME voltage coefficient increases with increasing t M , but reaches to a peak value and then decreases with increasing D$ \bar{D}$. It is indicated that the ME effect of trilayered cylindrical composite is less than that of bilayered one, possibly due to its symmetric structure. Under clamped condition, the resonance frequency will shift to a very high value for both trilayered and bilayered cylindrical composites, while the ME effect has different performance, enhanced in bilayered but suppressed in trilayered cylindrical composite. Our model shows that one can obtain strong ME effect and proper resonance frequency by selecting suitable materials, optimizing its geometry structure and varying mechanical boundary conditions for the cylindrical composite structure

Magnetoelectrical effect in layered composites PbZr0.53Ti0.47O3-Mn0.4Zn0.6Fe2O4

The magnetoelectric (ME) effect in two- and three-layered composites made up of polarized ceramic plates of lead zirconate-titanate PbZr0.53Ti0.47O3 (PZT) and manganese-zinc ferrite Mn0.4Zn0.6Fe2O4 (MZF) has been studied. Dependences of the transverse ME voltage coefficient (α31) on the magnetostrictive layer thickness and the magnetic field intensity and frequency have been established. The mechanical coupling coefficient of the composite plates has been estimated. Results obtained for two-layered PZT-MZF structures have been analyzed using the method of efficient medium parameters.

Enhancement in the field sensitivity of magnetoelectric laminate heterostructures

The effect of magnetostrictive layer thickness on the magnetoelectric (ME) response and field sensitivity of Pb(Zr,Ti)O3-metglas based sandwiched ME heterostructures has been studied. Such structures hold promise for sensor applications. The increase in metglas thickness results in a significant increase in the ME response and magnetic field sensitivity. The ME coefficient and field sensitivity increase by about 1.5–1.75 and 2.7 times, respectively, for a structure with 150 μm thick six metglas layers on both sides of the Pb(Zr,Ti)O3, in comparison to a 50 μm thick two layered structure.

Buckling and free vibration analysis of magnetic constrained layer damping (MCLD) beam

This paper deals with buckling, free vibration and damping analysis of viscoelastic sandwich beam with constrained magnetostrictive layer. Eight node plane stress element is used for the analysis. The influence of viscoelastic core thickness and magnetostrictive layer thickness on the buckling and dynamic analysis of sandwich beam under magnetic environment is analyzed by considering the initial stresses due to uniform magnetic field. The validation is carried out using commercial package ANSYS 8.1, based on the thermal analogy concept given by Cote et al. [Dynamic and static modeling of piezoelectric composite structures using a thermal analogy with MSC/NASTRAN, Compos. Struct. 65 (2004) 471–484].

Simulation of magnetostriction in TbFe 2/Fe multilayers

In this paper, micromagnetic simulation is used to study the magnetostrictive and magnetic character of a TbFe 2/Fe multilayer. The influence of magnetic easy-axis orientation, thickness of the TbFe 2 layer and number of layers of the multilayer are examined in detail. According to our numerical results, some general rules to improve the performances of magnetostrictive multilayers are determined which can be stated as: perpendicular easy-axis orientation of two kinds of sub-layer, proper magnetostrictive layer thickness, and more film layers.