Small particles, with various average sizes (140 to 680nm), were prepared by using a gas-evaporation method. Powder X-ray diffraction patterns showed that they were a mixture of γ- and β-phases, and that the mass fraction of the latter was 20 to 25%. The room-temperature conductivity of a polycrystalline pellet of small particles exhibited increases with decreasing particle size, and a conductivity of 1.4 x 10−4S/cm was found for 140nm grain-size polycrystals. The overall activation energy for conduction ranged from 0.38 to 0.28eV; depending upon the average size of the particles.

Ionic Conductivity of Small-Grain Polycrystals of Silver Iodide. T.Ida, K.Kimura: Solid State Ionics, 1998, 107[3-4], 313-8