Electric Field Control of the Magnetic Order of Flexible PVDF-Nickel Ferrite Composite Nanofibers

Materials consisting of two ferroic orders ferroelectricity and ferromagnetism have gained huge interest in developing multifunctional devices such as magnetoelectric sensors, actuators, energy harvester, and magnetic memory. However, the lack of flexible materials with a strong magnetoelectric coupling effect makes the use of the multiferroic system difficult for flexible wearable electronic devices. Here, we fabricate a flexible polyvinylidene fluoride-nickel ferrite (PVDF-NFO)-based polymer composite nanofiber and demonstrate electric field control of magnetic order. At room temperature (300 K), the coercive field increases progressively with applied DC electric field from 6.1 Oe (0.8 kV cm −1 ) to 9.9 Oe (1.2 kV cm −1 ) and 14.6 Oe (1.4 kV cm −1 ), corresponding to an overall enhancement of ∼139%, with sensitivity of 14.1 Oe/ kV cm −1, compared to the 0.8 kV cm −1 state. In addition, 96.5% modulation in the remanent magnetization has been achieved (at 300 K), further confirming the effective magnetoelectric coupling control of magnetic order in the nanofiber system. These results highlight the potential of PVDF-NFO composite nanofibers for flexible magnetoelectric devices, including sensors and memory applications.