Dielectric relaxation in polyaniline–polyvinyl alcohol composites

Abstract The dielectric relaxation spectroscopy of HCl-doped PANI–PVA composites have been investigated in the temperature range 110–300 K and in the frequency range 200 Hz–10 MHz near the percolation threshold. A large value of the dielectric constant has been observed at high temperature and low frequency. The complex dielectric constant ϵ ∗ (ω) has been described by the electric modulus M ∗ (ω)=(1/ϵ ∗ (ω))=M′(ω)+ i M″(ω) . The data of M ∗ (ω) has been analysed by the stretched exponential decay of the electric field, φ(t)=exp−(t/τ0)β, where 0