We have investigated relaxation dynamics of lithium ions in lead bismuthate glasses in the frequency range from 10 Hz to 2 MHz and in the temperature range from 303–553 K. Using the Anderson-Stuart model, we have calculated the activation energy, which is observed to be lower than that of the dc conductivity. We have studied the relaxation mechanism of these glasses in the framework of the electric modulus and conductivity formalisms. The microscopic parameters obtained from these formalisms have been compared. We have also calculated the decoupling index and correlated them with the stretched exponential relaxation parameter and the dc conductivity.

• Received 27 January 2000

DOI:https://doi.org/10.1103/PhysRevB.62.3190