Dielectric properties of poly(vinylidene fluoride)-based nanocomposites containing a LaFeO₃ nanoparticle filler

Flexible dielectric polymer nanocomposites have been widely investigated in recent years due to their potential application in electronic devices. In this study, a new system of flexible composites is prepared by incorporating the orthorhombic perovskite structure of a LaFeO₃ (LFO) filler into poly(vinylidene) fluoride (PVDF). LFO nanoparticles with an average particle size of ~ 194 nm are synthesized by the combustion method. The effect of the introduced LFO on the morphology, structure, phase composition, and dielectric properties of the composites is investigated. The LFO/PVDF nanocomposites show a large dielectric permittivity, which is approximately 5 times higher than that of pure PVDF. Interestingly, the dielectric loss tangent of the composites is decreased by ~ 0.059 at a volume fraction of LFO (f_LFO) = 0.5, temperature of ~ 20 °C, and frequency of 1 kHz. The improved dielectric properties of the LFO/PVDF composites can be explained by the presence of strong interfacial polarization and the increase in the polar β-PVDF phase in the nanocomposites. This work provides a comprehensive guideline for improving dielectric polymer nanocomposites with high permittivity and low dielectric loss.