Thermal diffusion of strontium ions in sodium chloride crystals

Abstract

The thermal diffusion of tracer amounts of strontium chloride has been measured in the temperature range 600–750°C in single crystals of sodium chloride, both pure and doped with 2–4 × 10^–4 mole fraction of strontium chloride, by means of Soret effect measurements. The mean value for the heat of transport of a strontium ion-cation vacancy complex was –1.56±0.15 eV and did not vary significantly with temperature within the accuracy of the results. The molecular interpretation of this quantity is discussed.