Electric modulus and AC conductivity studies in conducting PPy composite films at low temperature

Dielectric properties and electrical conductivity of some conducting polypyrrole (PPy) composite films in the temperature range of 180300 K and in the frequency range of 20-10(5) Hz have been reported. The experimental dielectric data have been analyzed in the light of electric modulus formalism. The electric modulus representation shows well-defined relaxation peaks. The conductivity relaxation energy as well as the AC conductivity activation energy was found to decrease as the PPy content increased. The frequency-dependent conductivity behavior at different temperatures provides a qualitative description of the conduction mechanism. The relaxation, occurs as a result of the hopping of charge carriers between localized states and the correlated barrier hopping model, describes the dominant mechanism. (C) 2003 Elsevier Ltd. All rights reserved.