Ionic Conductivity of Lead Chloride Crystals

Abstract

The ionic conductivity of single crystals of pure and KCl- and NaCl-doped PbCl 2 has been measured between 90 and 400°C. The thermal disorder appears to be of unassociated Schottky defects. The expressions for the "mobility" µ and the "concentration" x n 0 of anion vacancies have been determined from a comparison between the observed isothermals and those predicted from the simple theory of Koch and Wagner in which association effects are omitted. The experimental expressions are \begin{aligned} \mu{=}(2.6\times 10^{-1}/T)\exp(-0.20\pm 0.03/kT)\ \text{cm}^{2}\ \text{volt}^{-1}\ \text{sec}^{-1} \end{aligned} and x n 0 =2.7×10 2 exp (-0.51±0.05/ k T ) in mole fraction, where k T is expressed in electron-volt. These are the first results, expressed as a function of temperature, for anion vacancies in PbCl 2 crystals.