Flexible PVDF–NCMF nanocomposites: a synergistic approach to enhanced magneto-dielectric properties and sensing performance†

Fundamentally understanding and critically resolving magnetic domain interactions are essential for the successful application of multiferroics in future nanoscale electronics and magnetoelectronics. In this context, herein, we report on the magnetic domain interactions at the nanoscale in flexible and free-standing 0–3 nanocomposite films of polyvinylidene fluoride (PVDF)–Ni_0.93Co_0.02Mn_0.05Fe_1.95O_4−δ (NCMF) along with their performance characteristics. The PVDF–NCMF composites were synthesized by varying the chemical composition by means of the filler NCMF concentration in the PVDF matrix. The magnetic force microscopy (MFM) studies indicate the variation in the MFM-domain microstructure under varying fields. Combined MFM and magnetic measurements allowed us to elucidate the effective magnetic properties of the PVDF–NCMF composites as a function NCMF concentration. The magnetocapacitance (MC) and magnetoresistance (MR) of the composites were found to be in direct correlation with the chemical composition, particularly the NCMF content in the PVDF–NCMF composite. For 50 volume percentage (50%) of NCMF at 50 Oe, substantial MC and MR values of −3.1% and 4.4% were obtained at 10 kHz. The values rise more noticeably to −10.8% and 17.1% at 1000 Oe. The PVDF–NCMF composites demonstrated good sensing performance even at a modest magnetic field of 50 Oe indicating their potential for utilization in various multifunctional devices like memory devices, magnetic sensors, and bio sensors.