Dual-Peak Self-Biased Magnetoelectric Couplings in Tb<sub>0.3</sub>Dy<sub>0.7</sub>Fe<sub>1.92</sub>/Pb(Zr,Ti)O<sub>3</sub>/SmFe<sub>2</sub> Symmetrical Multiferroic Heterostructures

Abstract

A trilayer magnetoelectric (ME) composite consisting of a soft piezoelectric PZT-5H plate, a magnetostrictive Terfenol-D plate, and a rare-earth ferromagnetic Samfenol plate is fabricated and characterized for studies on the multipeak self-biased ME effects. In this symmetrical magnetostrictive/piezoelectric heterostructure, high shear-stress transfer to excite the bending resonance mode is induced by the magnetostrictive materials with opposite signs of magnetostriction, and a large internal anisotropic field is provided by a Samfenol plate due to its distinct ferromagnetism and magnetostriction. Consequently, hysteretic behavior can be simultaneously observed at both bending vibration resonance and transverse vibration resonance. Results demonstrate that the nonzero remnant ME coefficients of 0.7 and 2.23 V/Oe occur at bending frequency of 42.2 kHz and transverse frequency of 108.3 kHz, respectively, and the estimates of resonance frequencies are in agreement with the data. These characteristics provide the promise of this dual-peak self-biased symmetrical multiferroic heterostructure for low frequency magnetic field detection without the benefit of additional permanent magnets.