Diffusion of Ag ions under random potential barriers in silver-containing chalcogenide glasses

We show that a random walk model of diffused ions interprets well the experimentally deduced Nyquist plots in ionic chalcogenide glasses. Fitting of the model to the experimental data in the Nyquist plots of Ag-As-S(Se) glasses taken as case examples yields important physical parameters such as number of mobile Ag+ ions, hopping relaxation time and diffusion coefficient. It was found that the number of freely moving Ag+ ions is almost independent of Ag content in Agx (As0.33S(Se)0.67)100-x glasses, while the maximum hopping relaxation time is highly dependent on Ag concentration. (paper)