New models for impurity tracer diffusion in silver halides

A summary of results on diffusion of both anionic and cationic impurities in the silver halides is reported. The diffusion of bromide and iodide ions in silver chloride and of chloride and iodide ions in silver bromide are discussed in terms of two vacancy mechanisms. An interstitial-substitutional model is presented to explain the diffusion of divalent cations in silver halides. The effect of a chlorine atmosphere on the diffusion of gold ion in silver chloride is examined in terms of a deviation from stoichiometry.