NiV2O6-incorporated poly-(3,4-ethylenedioxythiophene) polymer nanocomposite: Synthesis, characterization, temperature dependent dielectric property and ac-conductivity relaxation behavior

Abstract

Triclinic variety of nickel vanadium mixed oxide (NiV2O6) (particle size: 120–140 nm) was synthesized via combination of sol-gel and calcination method, and incorporated by in-situ polymerization of ethylene dioxythiophene to poly-ethylene dioxythiophene (PEDOT) matrix for reinforcement. Materials were characterized by powder x-ray diffraction and different microscopic methods such as high resolution transmission electron microscopy, Fourier transform infrared spectroscopy etc. Temperature dependent dielectric constant and ac conductivity measurements of optimized sample were carried out. The composite materials showed appreciably high dielectric constant (up to 2 × 104) compared to that of pristine PEDOT (∼32) and NiV2O6 (∼130). AC-conductivity analysis of the composite showed a steep rise with frequency, indicating the enhanced activity of trapped charges at higher frequency in grain and grain boundary. Thermally activated polarons with different activation energies in the regions of grain and grain boundary of the material are responsible for the enhanced electrical conductivity of NiV2O6-PEDOT nanocomposite. The variation of ohmic conductivity (σ′) with temperature reflected the said behavior as indicated by the grain and grain boundary resistances.