Dielectric Relaxation Spectroscopy and AC Conductivity of Doped Poly (Vinyl Alcohol)

The dielectric properties and AC conductivity of pure and doped PVA samples with different concentrations of CuCl2 and Thiourea are investigated in the frequency range from 0.2 Hz to 100 kHz within a temperature range from room temperature to 433 K. It is observed that the dielectric constant decreases with an increase of frequency for all samples. The behaviour of the dielectric loss (ε'') as a function of temperature at certain frequency revealed that, pure PVA sample is characterized by existence of two different relaxation process and doped PVA samples are characterized by a broad relaxation peak. The conductivity of pure and doped PVA samples is investigated at different temperatures. The values of the exponent n, suggest that the hopping mechanism dominates at lower temperature (from room temperature to nearly glass transition temperature).