Fast ion transport in silver halide solid solutions and multiphase systems

Abstract

The incorporation of homovalent ions, e.g., I− in AgBr, leads to a substantial increase in ionic conductivity σ. The charge compensation concept does not explain the enhancement. AgBr+30 mol. % AgI exhibits σ∼7 Ω−1 cm−1 at 380 °C, which is ∼170% larger than that of α‐AgI, the best known supersonic conductor, at its melting point. The purely elastic displacement caused by the foreign ion is suggested to be the origin of such a unique behavior. Furthermore, AgI‐AgBr two‐phase systems display σ∼103 times higher than predicted by the classical theories.