Macroscopic Room-Temperature\nMagnetoelectricity in\nPiezoelectric (Core)–Ferrimagnetic (Shell) Nanocomposites

The magnetoelectric (ME) effect, which involves the interaction\nof magnetic and electric fields within a material, has a significant\npotential for various applications. Our study addresses the limitations\nof conventional magnetostriction-based ME materials by demonstrating\nan alternative approach that achieves substantial ME effects in core–shell-type\nnanocomposites at room temperature. By synthesizing ferrimagnetic\nFe<sub>3</sub>O<sub>4</sub> nanoparticles onto piezoelectric poly(vinylidene\nfluoride) (PVDF) particles, we identified a distinct ME mechanism.\nIn magnetorheological (MR) fluids, the magnetic-field-induced aggregation\nof Fe<sub>3</sub>O<sub>4</sub> nanoparticles, combined with the piezoelectricity\nof PVDF, leads to a pronounced ME effect, significantly enhancing\nthe performance and stability of MR fluids. This research highlights\na crucial observation of distinct ME effects, which could suggest\npotential pathways for advancements in practical applications including\nmicrofluidics, vibration dampers, tactile technologies, and biomedical\nand bioengineering fields.