AC conductivity and dielectric relaxation studies in AgI-based fast ion conducting glasses

AC conductivity and dielectric relaxation in AgI-based fast ion conducting glasses have been examined in four systems: AgI-Ag2MoO4, AgI-Ag3AsO4, AgI-AgPO3 and AgI-Ag2O-V2O5. Dielectric relaxation is examined using modulus formalism. Suitability of stretched exponential relaxation function has been investigated. Inverse relation has been found to exist between the stretching exponent and the structural unpinning number which characterizes fast ion conduction. Physical origin of correlated states, relevance of cluster-tissue model of glasses and the role ofstructural unpinning concept have been examined in the light of dielectric behavior of AgI-based glassy fast ion conductors