Ferroelectric Switching and Fatigue Response in <scp>PVDF–TrFE</scp> Using Nickel Electrodes: A Multiferroic Composite

ABSTRACT The search for multiferroics is an emerging research area where the emphasis is on integrating well‐known multifunctional constituent materials. In this work, we investigated the influence of Ni as electrode material on the detailed electrical properties of poly (vinylidene fluoride/trifluoroethylene) (PVDF–TrFE) polymer films with a 70/30 M ratio. PVDF–TrFE films with variable thicknesses were fabricated. Structural phase analysis confirms the formation of the well‐known ferroelectric β ‐phase. For direct comparison and interpretation, we also present the same analysis for free‐standing films with Pt electrodes. The electrical responses of free‐standing films with Ni and Pt electrodes exhibit largely similar features. These features include glass transition, ferroelectric phase transition, ferroelectric hysteresis, and fatigue characteristics. However, dielectric and ferroelectric responses were relatively better in films with Pt electrodes, likely due to the non‐reactivity of Pt with the polymer and the tendency of Ni to develop an interfacial oxide layer at the Ni/PVDF–TrFE interface, which can hinder charge accumulation and reduce the effective polarization. These results suggest that the choice of electrode material has a significant impact on the ferroelectric performance of PVDF–TrFE films, with Pt electrodes emerging as a preferable choice for practical applications. Nevertheless, the observation of good results with Ni electrodes opens a promising avenue for their use as composite materials, providing insights into the development of novel flexible ferromagnetic/ferroelectric multiferroics.