Epoxy modulated multifold enhancement of magnetoelectric response in distributed disc structured composite

The authors had previously reported a novel magnetoelectric (ME) composite configuration termed as distributed disc structured (DDS) configuration, which was proposed as epoxy-free ME composite to enable them to operate at elevated temperatures. However, a topological study on the epoxy-free DDS composites reveal that the absence of epoxy led to material discontinuity and generation of voids at the magnetostrictive/piezoelectric interface, thereby adversely affecting the output ME response. In this study, the voids at the magnetostrictive/piezoelectric interface in the DDS composites have been filled using epoxy material and quasi-static and resonant ME measurements show a remarkable improvement over their epoxy-free counterparts. The maximum ME coefficient of 2.33 V/cm Oe (enhancement of 430 %) and a peak value of 163 V/cm Oe is observed for four-disc structured configuration under quasi-static and resonant operating conditions, respectively. Thus, for the first time, the advantage of the DDS configuration has been combined with the use of epoxy leads to achieve a remarkable enhancement in ME response of Ni/PZT composites.