Enhanced Sensitivity With Five-Phase Heterostructure Magnetoelectric Sensor at Low Magnetic Bias Field

Abstract

In this paper, we have proposed a five-phase heterostructure magnetoelectric (ME) sensor with high-permeability Fe-based nanocrystalline soft-magnetic alloy FeCuNbSiB, ferromagnetic alloy with constant elasticity FeNi and piezoelectric ceramic lead zirconium titanate (PZT). A built-in magnetic field induced by a spatially varying magnetization within the heterostructure leads to a zero-biased ME response. The corresponding zero-biased ME coefficient reaches as high as 43.75 V/ $\text {cm}\cdot \textrm {Oe}$ (3.5 V/Oe). Meanwhile, an additional stress produced by FeCuNbSiB is transferred to FeNi, which enhances the effective resonant strain coefficient for FeCuNbSiB/FeNi at low magnetic bias and decreases the required optimum dc magnetic bias $H_{\mathrm{opt,dc}}$ . Hence, the maximum resonant ME coefficient is found to reach 51.5 V/ $\text {cm}\cdot \textrm {Oe}$ (4.12 V/Oe) at $H_{\mathrm{opt,dc}}$ of only 33 Oe. $H_{\mathrm{opt,dc}}$ for our proposed ME sensor is about one-tenth of that for FeNi/PZT/FeNi. Correspondingly, the five-phase heterostructure ME sensor is able to possess the strong ME sensitivity at low bias or even zero bias.