The Concentration and Mobility of Vacancies in Sodium Chloride

Abstract

The electrical conductivity of sodium chloride, containing cadmium chloride as an impurity, has been determined as a function of temperature. From these data it is calculated that the mobility of the positive ion vacancies is given by the equation μ=(19600/T)exp(−9860/T) cm.2/volt-sec. between 250°C and 400°C. The concentration of positive ion vacancies in a ``pure'' sodium chloride crystal was 1.0×1017 cm−3 and independent of temperature below 550°C.