non-stoichiometric oxides

The dependence of thermal expansion on the composition and atmosphere for molybdenumdoped lanthanum-strontium cobaltite La0.6Sr0.4Co1−xMoxO3−δ (х = 0–0.10) was studied by in situ hightemperature X-ray diffraction method (HTXRD). The linear coefficients of thermal expansion (CTE) were determined in air in the temperature range of 30–750°C. The linear dependence of the unit cell parameters on the molybdenum content was observed for the entire range of compositions, which obeys Vegard’s law and indicates the formation of solid solutions.

Doped with tantalum cations a new prospective cathode material for solid oxide fuel cells of lanthanum strontium cobaltite was synthesized. High-temperature oxygen desorption was studied using the quasi-equilibrium oxygen release method, the ranges of oxygen nonstoichiometry were determined, and the values of thermodynamic functions of the system were obtained in the temperature ranges (600–850°C) and oxygen partial pressures (∼10−5– 0.2 atm).