Large Magnetoelectric Effect in FeCuNbSiB/FeGa/PZT Multilayer Composite at Low Optimum Bias

We report a large magnetoelectric (ME) effect in FeCuNbSiB/FeGa/PZT multilayer composite at low optimum bias magnetic field (Hdc). Due to the great differences in the magnetic permeability and coercivity between FeCuNbSiB foils and FeGa alloys, the strong magnetization gradients are achieved, which induce an additional internal magnetic field in FeGa alloys. As a result, the optimum Hdc of FeGa/PZT composite decreases dramatically by attaching multilayer FeCuNbSiB foils. The experimental results demonstrate that: 1) the optimum Hdc of FeCuNbSiB/FeGa/PZT composite with one layer FeCuNbSiB foil reaches 62 Oe, which is only one-tenth of that of FeGa/PZT composite (606Oe); 2) the maximum ME voltage coefficient (MEVC) at resonance (α_ME,r) of FeCuNbSiB/FeGa/PZT composite with four-layer FeCuNbSiB foils can reach 115.8V/cm Oe, which is ~2.3 times higher than that of FeGa/PZT composite; and 3) the maximum zero-biased MEVC at resonance (α_ME,zero) is up to 58.2 V/cm Oe for FeCuNbSiB/FeGa/PZT composite with four-layer FeCuNbSiB foils. It provides great opportunities for such potential applications as the small-size and high-performance magnetic field sensors.