Synthesis and Investigation of Physical and Chemical Properties of Nanopowders and Ceramics in the La2O3–SrO–Ni(Co,Fe)2O3 System.

By the joint crystallization of solutions of nitrate salts, fine powders of La_{1 – x}Sr_xNiO₃, La_{1 ‒x}Sr_x-CoO₃, and La_{1 –x}Sr_xFe_0.7Ni_0.3O₃ (x = 0.30 and 0.40) are synthesized. They have a specific pore volume of 0.018–0.035 cm³/g and a specific surface area of 15–31 m²/g. On their basis, ceramic nanomaterials of a given composition with CSR ~ 64–70 nm (1300°С) are obtained. The physicochemical properties of the obtained ceramic are studied; it is revealed that the ceramic is a solid solution with open porosity in a range of 17–30% and a high value of the relative density of 94%. In terms of their physicochemical properties (open porosity, density, coefficient of thermal expansion), the obtained ceramic materials are promising as solid oxide cathodes for intermediate-temperature fuel cells. [ABSTRACT FROM AUTHOR]