Fabrication of SrW-Hexaferrite/Poly(vinylidene fluoride) Flexible Nanocomposite Films as Magneto-Mechano-Electric Generators for Self-Powered Magnetic Sensors

Abstract

Strain-mediated magneto-mechano-electric (MME) coupling in flexible biphasic heterostructures offers a powerful, noncontact pathway for the active tuning of ferroelectric and piezoelectric states. In this study, we report the fabrication and comprehensive characterization of SrW-type hexaferrite (SrCo2Fe16O27) nanoparticle-incorporated poly(vinylidene fluoride) (PVDF) nanocomposite films. The hexaferrite nanoparticles, synthesized via the sol–gel method and refined through ball milling, were dispersed within the electroactive PVDF matrix. XRD analysis and FESEM micrographs reveal the reduction of the average crystalline diameter of hexaferrites from 33.31 to 13.87 nm due to the mechanical milling method. FTIR spectroscopy confirms that increasing magnetic nanofiller loading enhances the polar β-phase within the PVDF matrix. A static magnetic study reveals a maximum of ∼14 emu/g of magnetization for the nanocomposite film at RT. The laminated nanocomposite architectures exhibit robust electric field-induced polarization, confirming their intrinsic ferroelectric ordering. Crucially, room-temperature evaluations reveal a magnetic field-driven expansion of the polarization hysteresis and an amplified piezo-response. This demonstrates a synergistic magneto-mechano-electric (MME) coupling, governed by highly efficient, strain-mediated energy transfer across the SrW-type hexaferrite–PVDF interface. By successfully translating magnetic stimuli into enhanced electric polarization yield, these flexible heterostructures emerge as highly promising candidates for advanced magnetic sensors, actuators, and dynamically tunable microelectronics.