Transverse Magnetoelectric Coefficient Research Articles

The influence of the electric field on the magnetoelectric response of a layered ferromagnet – electrostrictor heterostructure

Samples of piezoactive composition 0.89PbMg0.33Nb0.66O3 (MZF)−0.11PbZr0.48Ti0.52O3 (PMN–PZT) by two-stage ceramic technology were obtained. The values of the effective piezomodule d31 = (600–1400) pC/N for the resulting material significantly exceed the values of d31 = 150 pC/N for the commercially available family of lead zirconate – titanate ceramics even at low bias electric field strength. The dependence of the piezomodule on a dc electric field allows controlling the magnetoelectric coefficient without a bias magnetic field. Increase in the transverse magnetoelectric coefficient α31 in the MZF–PMN–PZT layered structure with a dc electric field shows the contribution of electrostrictive deformation to the magnetoelectric conversion in the absence of a bias magnetic field.

Anisotropy of Magnetoelectric Properties of Ferrite–Piezoelectric Bulk Composites

The anisotropy of magnetoelectric properties of lead zirconate–titanate and nickel ferrite based bulk composites has been experimentally studied. It has been shown that a ratio of longitudinal to transverse magnetoelectric coefficients is affected by the piezoelectric constant of a composite. The mechanism that explains the obtained dependences has been suggested; the mechanism is based on the assumption that the anisotropy of magnetic properties is caused by the deformation occurring at electric polarization of a sample.

Large Longitudinal Magnetoelectric Effect in Clamping Structure of TbDyFe Flake, Pb(Zr,Ti)O<sub>3</sub> Ring

Longitudinal magnetoelectric (ME) effect has been studied in a clamping structure of a magnetostrictive TbDyFe (Terfenol-D), a piezoelectric Pb(Zr,Ti)O3(PZT) ceramic ring. The ME coupling originates from the magnetic-mechanical-electric transform of the magnetostrictive effect in Terfenol-D and the piezoelectric effect in PZT by endpoint bonding, without adhesive layer. In such a clamping structure, Large induced voltage was measured without amplifier, Large longitudinal ME coefficient of 0.12V cm-1Oe-1was obtained at f =1 kHz, which is about 3 times larger than transverse ME coefficient of conventional layered Terfenol-D/PZT composites under the same measuring conditions. The ME coefficient reaches a maximum value at the dc bias magnetic field (Hdc) =280 Oe, which is lower than Hdc =350 Oe in conventional layered composites. The results show that large ME coupling can be achieved without adhesive layer, and longitudinal ME effect can be better than transverse ME effect.

Resonance magnetoelectric effects in magnetostrictive-piezoelectric three-layer structures

A theory is discussed for magnetoelectric (ME) interactions at electromechanical resonance in a heterogeneous ferromagnetic-piezoelectric three-layer structure. An expression has been obtained for the transverse ME coefficients αE,T as a function of interface coupling β between the layers. For 0<β<1, the theory predicts resonance enhancement of αE,T at two interrelated radial modes. As β is increased from 0, the low-frequency resonance occurs at progressively increasing frequency until it merges with the high-frequency mode when β=1. These predictions are in general agreement with representative data for a permendur-PZT-permendur trilayer composite.