Enhanced magnetoelectric effect in Metglas/K0.5 Na0.5NbO3/metglas lead-free ME laminates

We report the magnetoelectric (ME) coupling in lead-free ME composites composed of Metglas (2605SA1) and K0.5Na0.5NbO3 (KNN) phases. Thickness of the magnetostrictive layers (tm) is changed by stacking number of Metglas layers (t=25μm for each layer) while KNN is maintained at a fixed thickness (tp=300μm). As the number of Metglas layers increased, the peak magnitude of αME first increases, reaches a maximum and then decreases afterward. The static magnetic field (Hm), where αME shows maximum magnitude shift toward a higher value as number of layers increases. The maximum value of αME= 91mVcm−1Oe−1 is observed for optimized thickness ratio of tm/tp= 1 (i.e. n= 5 layers) at Hm= 160Oe. The αME is further enhanced by taking advantage of magnetic flux concentration effect of Metglas as a function of its sheet aspect ratio. The present composites can offer promising opportunities of engineering environmental friendly ME laminate for applications in ME devices such as energy harvester and magnetic field sensors.