Magnetostrictive-piezoelectric Structure Research Articles

Comparative theoretical study of the resonance frequencies of the longitudinal-shear and torsion modes of the magnetoelectric effect in a two-layer magnetostrictive-piezoelectric structure Metglas / GaAs

The article is devoted to a comparative theoretical study of the frequencies of the electromechanical resonance (EMR) of the magnetoelectric (ME) effect in the magnetostrictive-piezosemiconductor structure Metglas / GaAs of the longitudinal-shear and torsional modes. It is found that the resonance frequencies for the torsional mode are approximately 2 times higher than the corresponding frequencies for the longitudinal-shear mode. Therefore, it is quite possible to observe the torsional mode of the ME effect against the background of the longitudinal-shear mode, since the resonance frequencies are well distinguishable. The results obtained can find application in the construction of new ME devices.

Magnetoelectric effect in layered disk-shaped magnetostrictive–piezoelectric structures: Theory and experiment

Theoretical and experimental studies of the magnetoelectric effect in a disk-shaped magnetostrictive–piezoelectric structure in the electromechanical resonance region are presented. An expression for the magnetoelectric voltage coefficient is derived based on the simultaneous solution of elastodynamic and electrostatic equations separately for magnetostrictive and piezoelectric layers. The conditions at the interface were taken into account based on the premise that the interaction between layers is implemented by shear. It is shown that the inhomogeneity of the voltage and strain distribution over the sample thickness, caused by the interface, leads to a significant contribution to the effect in the case of thick layers. The theoretical and experimental dependences of the frequency characteristic of the effect are presented for the permendur–lead zirconate-titanate–permendur structure. The theoretical calculations are in good agreement with experimental data.

The magnetoelectric effect in the ring shape magnetostrictive-piezoelectric structures

We have theoretically and experimentally studied the direct magnetoelectric (ME) effect in ring structures made of volume ferrite–piezoelectric composites based on lead zirconate titanate and nickel ferrite. Analytical expressions for the ME voltage coefficient are obtained by jointly solving elastodynamic and electrostatic equations. Results of theoretical calculations and experimental measurements for various geometric parameters of the ring structures are presented.

Magnetoelectric Effect in Ferrite-Piezoelectric Dual-Phase Structure

This manuscript is devoted to the magnetoelectric coupling in a dimensionally graded magnetostrictive-piezoelectric structure in the electromechanical resonance region. Theoretical frequency dependence of ME voltage coefficient is obtained. Theoretical estimates for the layered structure of lead zirconate-titanate and single-crystal Zn0,3Ni0,7Fe2O4 are in satisfactory agreement with data. The obtained results are expected to facilitate observation of enhanced ME coupling at overlapping of electromechanical and magnetic resonance due to energy transfer between spin waves and phonons.

The influence of the adhesive bonding on the magnetoelectric effect in bilayer magnetostrictive-piezoelectric structure

The influence of the interlayer adhesive bonding is considered in bilayer magnetostrictive-piezoelectric structure. The expression for the frequency dependence of the magnetoelectric voltage coefficient in the electromechanical resonance region is obtained using the simultaneous solution of the motion equations for the magnetostrict- ive, adhesive, piezoelectric phases and material equations. It is shown that in the passage to the limits this expression for the coefficient transforms to the expression for ideal connection between the layers.

The nonlinear resonance magnetoelectric effect in magnetostrictive-piezoelectric structures

We have studied a magnetoelectric (ME) effect that is nonlinear with respect to the alternating magnetic field. It is established that resonance excitation of an alternating electric field takes place in magnetostrictive-piezoelectric bilayer structures under the action of alternating magnetic field at a frequency that is half as small as the electromechanical resonance frequency. The nonlinear ME effect, in contrast to the linear one, does not depend on the constant (magnetizing) bias field and is quadratic with respect to the alternating magnetic field.

Theory of magnetoelectric effect in a bilayer magnetostrictive-piezoelectric structure

A theory of the magnetoelectric effect in a bilayer magnetostrictive-piezoelectric structure is presented. As objects of research, structures in the form of nickel–lead zirconate–titanate and permendur–lead zirconate–titanate based plates are chosen. Joint solution of the motion equation for a magnetostrictive and piezoelectric medium and of the constitutive equations yields an expression for the magnetoelectric voltage coefficient in the region of electromechanical resonance.

Magnetoelectric effect in bilayer magnetostrictive-piezoelectric structure. Theory and experiment

Bilayer magnetostrictive-piezoelectric structures have certain advantages compared to bulk composites and this allows us to consider them as perspective materials for the development of devices based on the magnetoelectric effect. The theory of magnetoelectric effect in bilayer magnetostrictive-piezoelectric structure is presented taking into account the thickness dependence amplitude of the mechanical oscillations for the structures in form of rectangular plate. The equation for frequency dependence of the ME effect in the region on the electromechanical resonance was obtained, using motion equation, elastodynamics and electrostatic equations for the magnetostrictive, piezoelectric phases and taking into account the boundary conditions on the interface. The cases of longitudinal and transverse orientations of the electric and magnetic fields were considered. It is shown that the thickness dependence of the ME voltage coefficient has the maximum. The dependence between frequency and the thickness ratio of the layers is presented for both the theory and experiment.

Thin film magnetoelectric composites near spin reorientation transition

We report the use of a magnetic instability of the spin reorientation transition type to enhance the magnetoelectric sensitivity in magnetostrictive–piezoelectric structures. We present the theoretical study of a clamped beam resonant actuator composed of a piezoelectric element on a passive substrate actuated by a magnetostrictive nanostructured layer. The experiments were made on a polished 150 μm thick 18×3 mm 2 lead zirconate titanate (PZT) plate glued to a 50 μm thick silicon plate and coated with a giant magnetostrictive nanostructured Nx(TbCo 2 5nm/FeCo 5nm) layer. A second set of experiments was done with magnetostrictive layer deposited on PZT plate. Finally, a film/film structure using magnetostrictive and aluminium nitride films on silicon substrate was realized, and showed ME amplitudes reaching 30 V Oe −1 cm −1. Results agree with analytical theory.

Enhanced magnetoelectric effect in nanostructured magnetostrictive thin film resonant actuator with field induced spin reorientation transition

We report the use of a magnetic instability of the spin reorientation transition type to enhance the magnetoelectric sensitivity in magnetostrictive-piezoelectric structures. We present the theoretical study of a clamped beam resonant actuator composed of a piezoelectric element on a nonpiezo substrate actuated by a magnetostrictive layer. The experiments are made on a polished 150μm thick 18×3mm2 lead zirconate titanate (PZT) plate glued to a 50μm silicon plate and coated with a giant magnetostrictive nanostructured Nx(TbCo25nm∕FeCo5nm) layer. Another set of experiments was done with PZT substrate only. Results agree with analytical theory.

Magnetoelectric interactions in ferromagnetic-piezoelectric layered structures: Phenomena and devices

Layered magnetostrictive-piezoelectric structures are multifunctional due to their dual-responsiveness to mechanical and electromagnetic forces. Here, we discuss studies of magnetoelectric (ME) interactions in ferrite-lead zirconate titanate (PZT) and terfenol-PZT material couples. Key findings include: (1) the observation of a giant low-frequency ME effect in the layered systems; (2) data analysis based on our model for low frequency ME effects; (3) observation and theory of enhanced ME coupling at the electromechanical resonance (EMR); and (4) theory and measurements of microwave ME effects, at the ferromagnetic resonance of ferrites. The layered structures are potential candidates for sensors, gyrators and microwave devices. Low frequency sensors are feasible with excellent sensitivity to minute magnetic field variations. One could also realize composite based ferromagnetic resonance devices, such as resonators, filters and phase shifters with electric field tunability for use at 1–70 GHz.