Electrochemical Transient Investigations of the Diffusion and Concentration of Electrons in Yttria Stabilized Zirconia-Solid Electrolytes

Abstract

The voltage relaxation of galvanic cells with zirconia electrolytes polarized between an inert silver electrode and an Fe + FeO electrode has been analyzed to obtain the diffusion coefficient of the electronic minority charge carriers in the temperature range between 700 and 900 °'C. The method has been examined by using different thicknesses of the sample. At 800 °C the diffusion coefficient of the electrons is 1.4 x 10-3 cm2/sec, i. e., about two orders of magnitude higher than that for the holes, 4.5 x 10-6cm2/sec. The activation energy 0.55 eV is obtained for the electrons, compared to 1.4 eV for the holes. From conductivity data, the concentrations of electrons and holes at 800 °C and 1 atm oxygen partial pressure are calculated to be 1 x 109 and 4 x 1017 cm-3, respectively. The electronic band gap is evaluated to be 4.1 eV. © 1976, Walter de Gruyter. All rights reserved.