Large Self-Biased Magnetoelectric Properties in Heterostructure of Graded-Magnetostrictive Layers and a Rosen-Type Piezoelectric Transformer

This paper develops a magnetoelectric (ME) heterostructure FeCuNbSiB/Ni/Rosen-type piezoelectric transformer (RPT)/Ni/FeCuNbSiB consisting of a RPT Pb(Zr_1-xTi_x)O₃ with its drive-end sandwiched between two graded-magnetostrictive layers of FeCuNbSiB/Ni. The graded-magnetostrictive layer FeCuNbSiB/Ni is made up of Fe-based nanocrystalline alloy FeCuNbSiB (Fe_73.5Cu₁Nb₃Si_13.5B₉) and pure Nickel (Ni). Due to the different magnetic characteristics of FeCuNbSiB and Ni (such as permeability, saturation magnetization and magnetostriction), the FeCuNbSiB/Ni layer exhibits an internal magnetic bias field, which results in the large self-biased ME properties. An amplified output voltage can be obtained between the two electrodes of the generator-end due to the step-up voltage-gain effect of the RPT. Consequently, the maximum zero-biased ME voltage coefficients of generator-end are ~4.06 V/Oe at the first resonance frequency of ~41 kHz, and ~4.22 V/Oe at the second resonance frequency of ~102 kHz. The results show that this heterostructure is of interest for high-sensitive magnetic field sensors.