Effect of doping with iron and cations deficiency in the high conductive electrolyte La0.8Sr0.2Ga0.8Mg0.2O3–δ on oxygen exchange kinetics

• Published in: Solid state ionics 2024-12, Vol.417, p.116704, Article 116704
• Main Authors: Porotnikova, Natalia, Khodimchuk, Anna, Gordeev, Egor, Osinkin, Denis
• Format: Article
• Language: English
• Subjects: Cation substitution and/or deficiency; Electrolyte; LSGM; Oxygen diffusion; Oxygen isotope exchange
• ISSN: 0167-2738
• DOI: 10.1016/j.ssi.2024.116704

The oxygen isotope exchange method was used to investigate the kinetics of the interaction between gaseous oxygen and LaGaO3-based oxides in a temperature range of 650 to 850 °C, with an oxygen pressure of 10 mbar. The stable isotopes of 18O/16O were used as labelled ions. The temperature dependencies of the heterogeneous oxygen exchange rate (rH), the oxygen dissociative adsorption rate (ra), the oxygen incorporation rate (ri), and the oxygen diffusion coefficient (D) were determined. A comparative analysis of the rH and D values for La0.8Sr0.2Ga0.8Mg0.2O3–δ was carried out with a view to identifying any similarities or differences when compared with the literature data on oxides with similar compositions. The effect of FeGa′ doping and the creation of an A-sublattice deficiency on the kinetic characteristics were investigated using the (La0.8Sr0.2)0.98Ga0.7Fe0.1Mg0.2O3–δ oxide as a case example. Correlations between the rate-determining step of oxygen exchange and the modification of the oxide composition were identified. •The kinetic parameters of (La0.8Sr0.2)0.98Ga0.7Fe0.1Mg0.2O3-δ were studied.•The influence of composition modification on electrolyte properties was investigated.•The rate-determining stages of LSGM and LSGFM oxygen exchange were determined.•The oxygen exchange mechanism was changed by the introduction of iron into LSGM.