Characterization and regulation of Ni3Si//Fe3O4@PVDF magnetoelectric composites

Exploring new magnetoelectric (ME) composites and improving their forming methods are keys to overcome the development bottlenecks. This study constructed a novel pseudo 2–2 connectivity Ni3Si//Fe3O4@PVDF composite based on lamellar Ni3Si template under the pulsed magnetic fields and investigated the influences of Fe3O4 nanoparticles (NPs) content and the magnetic flux density peak (MP) on the ME properties. Ni3Si template provides additional stress for the magnetic-electric conversion and significantly enhances the ME properties. The increase of Fe3O4 NPs content leads to the improvement of interfacial strain transfer and the decrease of effective contact area synchronously. Therefore, ME coefficients of 3.63, 7.61 and 2.43 mV/(cm·Oe) were achieved with Fe3O4 NPs contents of 4.8 wt%, 7.9 wt% and 16.7 wt%. The pulsed magnetic field can increase the ordering of Fe3O4 NPs, but the induced particle aggregation reduces the interfacial coupling strength. If the MP is 4.5 T, the maximum ME coefficient is 8.35 mV/(cm·Oe), which is 2.27 times of that without magnetic field. But when MP increases to 8.9 T, the maximum ME coefficient is only 4.1 mV/(cm·Oe). Therefore, it is feasible to adjust the ME characteristics by varying the content of Fe3O4 NPs and the MP of the pulsed magnetic fields.