The effect of interfacial interaction-induced soft percolation regime on dielectric properties in Ba(Fe0.5Nb0.5)O-3/P(VDF-TrFE) nanocomposites

摘要

Polymer nanocomposites with low dielectric loss tangent and high discharge efficiency are highly desirable in electronic and electric industry. In this study, a nanocomposite with significantly soft percolation regime is realized by combining Ba(Fe0.5Nb0.5)O-3 with giant dielectric permittivity as a ceramic filler and poly(vinylidene fluoride-trifluoroethylene) as a polymer matrix. In the heterogeneous system, a soft percolation regime of a more gradual growth in dielectric constant is found at the volume filling fractions between 30 and 40 vol%. Meanwhile, the alternating current conductivity, D-E loops and discharge efficiency have been changed dramatically. It can be explained that there is an insulator-conductor transition due to the formation of continuous conductive paths among interfaces in the polymer nanocomposites. Additionally, it suggests that the interfacial interaction of nanocomposites must be carefully controlled to avoid the soft percolation regime and realize high discharge efficiency.