Synergistic effect of MoO3 conducting nanofillers on dielectric and electrical properties of P(VDF-HFP)-(Ba0.85La0.15)(Fe0.5Nb0.5)0.9625O3 composite films

Abstract

This study investigates the synergistic impact of MoO₃ as a conducting nanofiller on poly(vinylidene fluoride-co-hexafluoropropylene)/La³⁺ modified barium iron niobate (P(VDF-HFP)-BLFN) composites prepared by the solution casting technique. The dielectric and electrical performance of PVDF-HFP-BLFN-MoO₃ composite films with various weight percentages of MoO₃ content was studied. The structure and microstructure of the PVDF-HFP-BLFN-MoO₃ composite films were analyzed by X-ray diffraction and scanning electron microscopy techniques. The structural analysis verifies the existence of the polymeric electroactive β-phase of the matrix (PVDF-HFP) and the perovskite phase of the integrated ceramics within the matrix. The surface morphology of the synthesized composite exhibits distinct and evenly dispersed particles with little aggregation. A broad frequency range (10²–10⁶ kHz) was used to assess the dielectric and electrical characteristics of polymer composite films with varying MoO₃ concentrations. The use of MoO₃ markedly improved the dielectric constant while preserving a reasonably low dielectric loss, with optimum performance seen at 10 wt% ceramic content. The composites demonstrated frequency-dependent dielectric properties, ascribed to Maxwell-Wagner relaxation at lower frequencies and α-relaxation of PVDF-HFP at elevated frequencies. The increased characteristics arise from the synergistic interaction of the polymer matrix, ceramic particles, and conductive nanofiller, resulting in an improved interfacial polarization effect. These results show the capability of these nanocomposites for advanced energy storage and harvesting applications.