Symmetric relationships between direct and converse magnetoelectric effects in laminate composites

Direct magnetoelectric (DME) and converse magnetoelectric (CME) effects are two opposite processes in magnetoelectric (ME) materials. An ME theoretical model about the longitudinal vibration was proposed to research their relationships in a laminate composite based on equivalent circuit. Following the piezoelectric and magnetostrictive constitutive equations, we deduced magnetic-mechanical-electric equations, and then built a symmetric equivalent circuit about the ME coupling, based on which we analyzed the CME and DMD effects equivalently. A simple laminate composite was prepared by bonding Terfenol-D and Pb(Zr,Ti)O-3 plates together for a experimental research. Theoretical calculations meet the experimental results very well. The CME and DME effects exhibit enhanced energy transitions at the resonance frequency with a large phase shift of about it pi. The ME composite shows CME and DME frequency multiplying behaviors and inhomogeneous CME and DMD responses. The CME and DME as well as their resonance frequencies present nonlinear characteristics with the bias magnetic field. The CME resonance frequency is lower than the DME resonance frequency in a same sample. CME decreases while DME increases with the magnetostrictive layer. The theoretical model plays an important role in the comprehensive understanding of ME properties, especially the CME effect, and design of ME devices such as magnetic-electric field sensors, energy harvesting transducers and solid tunable transformers. (C) 2016 Elsevier Ltd. All rights reserved.