One‐Dimensional CFO Nanowires to Promote the Electric‐Field‐Induced Magnetic Modulation Properties of CFO @ BTO /P( VDF ‐ TrFE ) Composite

Abstract

ABSTRACT CoFe₂O 4 (CFO) nanowires and their BaTiO 3 ‐loaded counterparts (CFO@BTO) were synthesized via hydrothermal and sol–gel methods. The bare CFO nanowires, calcined at 850°C, exhibited a high saturation magnetization ( Mₛ ) of 70.9 emu·g −1 . Subsequently, the CFO@BTO nanowires were incorporated into a ferroelectric poly(vinylidene fluoride–trifluoroethylene) [P(VDF‐TrFE)] matrix via solution casting to form composite thick films. The resulting films showed an Mₛ of 38.2 emu·g −1 . The dielectric constant ( εᵣ ) of the composite increased with the CFO@BTO nanowire content, reaching a value of 40 at 100 Hz. Polarization–electric field (P–E) hysteresis measurements revealed that the introduction of CFO@BTO nanowires significantly enhanced the ferroelectric performance of the composite, yielding a remanent polarization of approximately 11.6 μC cm −2 under an electric field of 125 MV m −1 . Notably, the saturation magnetization of the CFO@BTO/P(VDF‐TrFE) composite film was markedly increased after electric‐field poling, indicating a polarization‐induced modulation of magnetic properties. This behavior suggests a correlated interaction between the ferroelectric phases (BTO and P(VDF‐TrFE)) and the ferromagnetic CFO nanowires. This work demonstrates an effective strategy for tuning magnetic responses in ferroelectric polymer‐based composites through nanostructure design and electric‐field polarization.