Dielectric properties of poly(vinylidene fluoride) nanocomposites filled with surface coated BaTiO3 by SnO2 nanodots

SnO 2 nanoparticles with an average diameter of about 4 nm were coated on the surface of BaTiO 3 (BT) (∼100 nm) by chemical treatment. With the introduction of BT@SnO 2 , the dielectric permittivity of poly(vinylidene fluoride) (PVDF) composite was significantly increased to 90 at 10 3  Hz, which is ∼40% higher than that of the BT/PVDF composites. It was attributed to the enhanced interfacial polarization in the interlayers between BT and PVDF due to the addition of SnO 2 nanodots. The distance of SnO 2 nanodots on the adjacent BT surfaces is close enough for the electron transport in the matrix by tunneling effect. Besides, the semiconductive SnO 2 leads to the weak insulating-conducting transition close to the percolation threshold.