Charge transport mechanism of vanadium pentoxide xerogel-polyaniline nanocomposite

摘要

The nanocomposites of conducting polyaniline are prepared by intercalating into the layers of vanadium pentoxide (V2O5) xerogel. The intercalation is confirmed by the observation of lattice expansion of V2O5 xerogel. Dc conductivity of the gel follows Arrhenius type temperature dependence while the nanocomposites exhibit three dimensional variable range hopping. The ac conductivity and dielectric properties are extensively studied at low temperature up to the frequency of 10 MHz. Two semicircles in Cole-Cole plot of impedance are found for the nanocomposites. The ac conductivity spectra reveal three frequency regions. The frequency exponent in the lower frequency region is nearer to 2. The dielectric response exhibit broad spectra which are analyzed by Cole-Cole distribution function. The peak frequency of dielectric spectra appears at the first cross over frequency of conductivity spectra.