THERMOELECTRIC PROPERTIES OF MOLTEN SILVER CHLORIDE-SILVER IODIDE EUTECTIC MIXTURE

The silver chloride-silver iodide equilibrium diagram has been constructed. The eutectic temperature is 259°C and the eutectic composition is 47 mole% silver chloride. The mean thermoelectric potential of this mixture between 260 and 960°C has been measured as -0·498 mv degK-1. Values of electrical conductivity of silver chloride-silver iodide mixtures are available in the literature, and the mean specific conductivity of the eutectic mixture between 260 and 960°C has been estimated as 2·91 Ω -1cm-1. The thermal conductivity has been measured as 1·83 × 10-3 W cm-1 degK-1 at 300°C. These values yield an approximate mean figure of merit for thermoelectric generation between 260 and 960°C of 0·4 × 10-3 degK-1. This is a threefold increase over the estimated figures of merit for the pure components.