Zero-Biased Magnetoelectric Effects in Five-Phase Laminate Composites With FeCoV Soft Magnetic Alloy

In this paper, large zero-biased magnetoelectric (ME) effects are experimentally demonstrated in a five-phase laminate composite consisting of high-permeability Fe-based soft magnetic alloy FeCoV, giant magnetostrictive material Terfenol-D, and piezoelectric ceramic Pb(Zr_1-x, Ti_x)O₃ (PZT). The coupling effects between FeCoV and Terfenol-D result in a build-in magnetic bias due to their different magnetic permeability and coercivity. As a result, an obvious increase in resonant ME voltage coefficient (MEVC) at zero dc magnetic bias field (H_dc) for FeCoV/Terfenol-D/PZT/Terfenol-D/FeCoV (FMPMF) composite is obtained. The experimental results demonstrate that the optimum zero-biased resonant MEVC (α_ME,r) of FMPMF composites with three-layer FeCoV foils can reach 19.6 V/cm Oe, which is 1.75 times as great as that of traditional Terfenol-D/PZT/Terfenol-D (MPM) laminate composites. A low-frequency MEVC (α_ME,l) of 176 mV/cm Oe is achieved, which is 2.45 times higher than that of the MPM laminate composites. The induced zero-biased ME voltage of FMPMF laminate composite shows an excellent linear relationship to ac magnetic field both at the low frequency (1 kHz) and the resonance frequency (115.14 kHz) over a wide range. This laminate composite shows promising applications for high-sensitivity and small-size magnetic-sensing devices without bias.