Effect of cation nonstoichiometry on the properties of solid electrolyte BaxCe0.97Nd0.03O3-δ (0.90 ≤ x ≤ 1.10)

The effect of the cation nonstoichiometry on the electroconduction, electrotransfer, and stability in humid air of solid proton-conducting electrolyte BaxCe0.97Nd0.03O3 - delta (0.90 less than or equal to x less than or equal to 1.10) is studied. The electroconduction is found to decrease with decreasing content of BaO (x less than or equal to 1.0) and weakly depend on the BaO excess (x > 1.0). Ceramics of a stoichiometric composition (x = 1) and with lack of barium is stable when stored in humid air at room temperature, as opposed to the ceramics with barium excess, which rapidly decomposes in these conditions. The conduction of materials under study in oxidizing environment is ion-hole and in reducing media, ionic (proton + oxygen). The cation nonstoichiometry barely affects the nature of the ion transfer. An analysis of possible models for the formation of defects shows oxygen vacancies to be always present in BaxCe0.97Nd0.03O3 - delta, even at the CeO2 excess exceeding the content of neodymium.