Superionic AgI–MIn–Sb2S3 glasses (M=Pb, Sb): conduction pathways associated with additional metal iodide

The ionic conductivity of the 0.5AgI·xSbI3·(0.5−x)Sb2S3 and 0.5AgI·xPbI2·(0.5−x)Sb2S3 glassy systems with a constant silver concentration has been investigated. It was found that the Ag+ ion transport is closely related to the heavy metal iodide content. The conductivity activation energy decreases from 0.38 to 0.28 eV, and the room temperature conductivity increases by a factor of 100 with increasing x. A structural model based on available neutron diffraction, EXAFS and 129I-Mössbauer spectroscopy data was proposed to explain the observed phenomena.