Significantly Enhanced Dielectric Properties of Ag-Deposited (In(1/2)Nb(1/2))(0.1)Ti(0.9)O(2)/PVDF Polymer Composites

The enhanced dielectric permittivity (ε′) while retaining a low loss tangent (tanδ) in silver nanoparticle−(In(1/2)Nb(1/2))(0.1)Ti(0.9)O(2)/poly(vinylidene fluoride) (Ag-INTO/PVDF) composites with different volume fractions of a filler (f(Ag-INTO)) was investigated. The hybrid particles were fabricated by coating Ag nanoparticles onto the surface of INTO particles, as confirmed by X-ray diffraction. The ε′ of the Ag−INTO/PVDF composites could be significantly enhanced to ~86 at 1 kHz with a low tanδ of ~0.044. The enhanced ε′ value was approximately >8-fold higher than that of the pure PVDF polymer for the composite with f(Ag-INTO) = 0.5. Furthermore, ε′ was nearly independent of frequency in the range of 10(2)–10(6) Hz. Therefore, filling Ag−INTO hybrid particles into a PVDF matrix is an effective way to increase ε′ while retaining a low tanδ of polymer composites. The effective medium percolation theory model can be used to fit the experimental ε′ values with various f(Ag-INTO) values. The greatly increased ε′ primarily originated from interfacial polarization at the conducting Ag nanoparticle–PVDF and Ag–INTO interfaces, and it was partially contributed by the high ε′ of INTO particles. A low tanδ was obtained because the formation of the conducting network in the polymer was inhibited by preventing the direct contact of Ag nanoparticles.