DIRECT DETERMINATION OF ELECTRICAL CONDUCTIVITY-NONSTOICHIOMETRY RELATIONSHIP IN IONICALLY CONDUCTING METALLIC OXIDES

The small quantities of oxygen driven off zirconia solid solutions by solidstate electrolysis were accurately measured and the relevant departure from stoichiometry determined by using oxygen gauges and pumps. The variations in the electronic conductivity and in the ionic transport number were determined as functions of temperature and deviation from stoichiometry. By measuring the rate of oxygen release during the first stage of the electrolysis of prereduced and homogenized samples, the ionic transport number was also determined according to another independent method. The two sets of results compared quite favorably. These methods of measurement offer the possibility of investigating nonstoichiometric oxides, especially in experiments involving small departures from stoichiometry and very reducing conditions. © 1978, The Electrochemical Society, Inc. All rights reserved.