THE ELECTROCHEMICAL-BEHAVIOR OF COMPACT INDIUM OXIDE ELECTRODES APPLIED ON SOLID OXIDE ELECTROLYTES

The electrochemical properties of compact In2O3 layers deposited on si ngle-crystal plates of the 0.9ZrO(2)-0.1Y(2)O(3) electrolyte are studi ed using impedance spectroscopy and measuring steady-state polarizatio n curves in air, at temperatures ranging from 795 to 1163 K. It is sho wn that, during anodic polarization, the electrode under study acts as a blocking electrode and the current is due to electronic conduction of the electrolyte. Two relaxation processes are observed in the frequ ency interval 0.01 Hz to 100 kHz, specifically, a high frequency proce ss characterized by the resistance R-eta(h) and a low-frequency proces s characterized by the resistance R-eta(1), with R-eta(1) much greater than R-eta(h). Applying PrO2-x on the surface of an In2O3 film makes its electrochemical activity grow by more than three orders of magnitu de, largely at the expense of a decrease in R-eta(1). Feasible paths a nd rate-determining stages of the oxygen reaction on the In2O3 films i n contact with 0.9ZrO(2)-0.1Y(2)O(3) are considered.