A New Magnetoelectric Composite with Enhanced Magnetoelectric Coefficient and Lower Resonance Frequency

This study reports large magnetoelectric (ME) effect by attaching Ni and Metglas magnetostrictive layers to one free end of piezoelectric Pb(Zr,Ti)O3 (PZT) cantilever. By this structure, the influences of the bonding layer can be weakened so as to get relatively high ME voltage coefficient (α_ME) at resonance frequency. And the cantilever structural magnetostrictive material can supply stronger magnetic force to the PZT plate instead of the shear force in traditional structure, leading to an enhancement of α_ME at resonance frequency and generate a new resonance frequency of bending mode which is lower. Also, it can be used without bias field due to the built-in dc magnetic bias field between Ni and Metglas layers. Hence, it can obtain a larger α_ME at a lower resonance frequency at zero bias. The resonant α_ME at zero bias of the new composite reaches 50 V/cm∙Oe which is about 1.5~2 times as large as that of the traditional one. Besides, it greatly enhances the α_ME in a frequency range between two resonance frequencies. When we changed the length and thickness of Ni or Metglas layers, the results changed with them. Both the length and thickness have the optimum number to get a maximal α_ME. We also find if Ni and Metglas layers are not side to side aligned, α_ME at zero bias will decrease a lot.