Enhanced dielectric properties and relaxation behavior in double perovskite-polymer-based flexible 0–3 nanocomposite films

The double perovskite nanostructures were prepared by using hydrothermal route to obtain single-phase rhombohedral structure. The flexible magneto-dielectric nanocomposite films with double perovskite La₂NiMnO₆ (LNMO) nanostructures and poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) polymer were fabricated by solution casting method. The structural, thermal, and dielectric properties of the developed double perovskite nanostructures and their combination with (PVDF-HFP) as nanocomposite films were investigated. The fabricated nanocomposite films demonstrated an improvement in the crystalline phase with the increase in the loading of La₂NiMnO₆ (0–40 wt%). The nanocomposite film with 30 wt% of LNMO exhibited higher dielectric permittivity (> 40) alongside with a dielectric loss of as low as 0.6 at room temperature and thereafter it reached percolation threshold. The dielectric studies also revealed an efficient charge separation and a strong interfacial polarization at the interfaces by facilitating the charge accumulation in the nanocomposites than that of the pure polymer film. The thermally activated relaxation behavior in the films followed the Arrhenius law and the obtained activation energies were found to be ~ 1.12 eV.