AC conductivity and its scaling behavior in lithium and sodium bismuthate glasses

Ac conductivity measurements and its scaling analysis is studied on the new sodium and lithium bismuthate systems xNa(2)O+ (1-x)Bi2O3 and xLi(2)O+(1-x)Bi2O3 for various compositions in the frequency range from 20 Hz to 1 MHz and in the temperature range from 467 to 750 K. The measured electrical relaxation data of these glasses are analysed using Jonscher's universal power law (UPL) and random free energy barrier model (RFEBM). All experimentally known features of the ac conductivity, including its scaling behavior, are explained satisfactorily based on the power law and random free energy barrier model. (C) 2002 Elsevier Science B.V. All rights reserved.