DIFFUSION OF ELECTRONIC DEFECTS IN CALCIA-STABILIZED ZIRCONIA FROM A DESORPTION RATE STUDY

Rates of desorption of oxygen from samples of calcia-stabilized zirconia (CSZ) have been measured as a function of oxygen saturation pressure, of temperature, and of the impurity content of CSZ. The results have been interpreted to determine the diffusion coefficient, D, for electronic defects in CSZ. D was independent of the oxygen saturation pressure from 0.5 to 101 kPa. The activation energy was 88 kJ/mol for one sample from 1228 to 1577 K and 113 kJ/mol for another from 1515 to 1667 K. D was inversely proportional to the iron impurity concentration in the CSZ. This observation was interpreted in terms of a mechanism in which electron holes were trapped by iron impurity sites. © 1990, The Electrochemical Society, Inc. All rights reserved.