Role of LGFO nanoparticles in improving dielectric and ferroelectric properties of PVDF

Developing flexible polymer-based dielectric materials with high energy storage efficiency is crucial for next-generation electronic and energy storage applications. In this study, poly (vinylidene fluoride) (PVDF)/La 0.75 Gd 0.25 FeO 3 (LGFO) nanocomposites were fabricated via a solution casting technique to explore their dielectric, thermal, and ferroelectric properties. The structural and morphological characterizations revealed the coexistence of the crystalline β-phase within the PVDF matrix and the orthorhombic phase of LGFO, indicating successful filler incorporation without any phase decomposition. The infrared spectra confirmed that LGFO incorporation effectively enhanced β-phase formation in PVDF, yielding the highest β-phase fraction (81.39%) at 20 wt.% filler content. An improvement in thermal stability with increasing filler loading was evidenced by the thermal results. The incorporation of LGFO nanoparticles (NPs) significantly enhanced the dielectric performance of the polymer, with the maximum dielectric constant reaching 84 at 100 Hz for the 20 wt.% composite. Impedance analysis indicated a deviation from ideal Debye behaviour, with grain effects governing the electrical response. At room temperature and under an electric field of 64 kV/cm, the 20 wt.% composite exhibited an energy storage efficiency of 82.21% and a discharged energy density of 1.741 J/cm 3 , about 8.4 times higher than that of pristine PVDF. The nanocomposites exhibit excellent dielectric and ferroelectric behaviour, making them promising for high energy-density applications.