Ionic Diffusion in Superionic Silver Compounds

Abstract

The diffusion constants of impurities, Cd⁺⁺ and In⁺⁺⁺ ions as well as the mobile Ag⁺ ions were measured in superionic α-Ag₂S, α-Ag₂Se and α-Ag₃SI with the α-AgI structure using tracers, ¹⁰⁹Cd, ¹¹¹In and ^106mAg. Unexpectedly, high mobilities were observed also for the multivalent impurity ions. The obtained diffusion constants of the Ag⁺ ions in α-Ag₂S and α-Ag₂Se are in good agreement with the reported values. It was concluded from the mobile ion dependence of activation energy for diffusion that in addition to the cation-anion and the electronic polarization, the repulsive and the cation-cation interaction play an important role in the interionic potential.