The fast-ion transition in FCC silver iodide

An analysis of previously reported data on electrical conductivity, adiabatic temperature change with pressure, and sound velocity confirms that the FCC phase of AgI has a fast-ion type II transition. This results in a steepening of the FCC/α-phase boundary which probably cusps in to a triple point at the α-phase order/disorder transition. Thermal expansion, compressibility and heat capacity are calculated for the FCC phase.