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Abstract—Highly dispersed mesoporous powders of the CeO2)1 – x(Nd2O3)x (х = 0.05, 0.10, 0.15, 0.20, 0.25) composition are synthesized by liquid methods such as coprecipitation of hydroxides and cocrystallization of nitrate salts. The powders have a specific pore volume of 0.030–0.111 cm3/g and a specific surface area of 7.40–119.26 m2/g. On their basis, ceramic nanomaterials of a given composition with CSR ~ 69–88 nm (1300°С) are obtained. The physicochemical properties of the resulting ceramic have been studied; it is revealed that it is a solid solution with open porosity in the range of 17–30% and high values of relative density of 89–96%. In terms of their physicochemical properties (density, thermal expansion coefficient), the resulting ceramic materials are promising as solid oxide electrolytes for intermediate-temperature fuel cells. [ABSTRACT FROM AUTHOR]

A composite material based on the B4C–SiC system with different initial carbon contents was obtained by reaction sintering (impregnation of a porous billet with liquid silicon). Carbon reacted with silicon to form a secondary silicon carbide that filled the space in the porous workpiece until a monolithic material was obtained. Boron carbide acted as the source of carbon if it was initially absent or its content was low. The obtained materials had the following characteristics: bending strength up to 320 MPa, density up to 2.85 g/cm3, microhardness up to 30 GPa. [ABSTRACT FROM AUTHOR]

Finely dispersed mesoporous powders of the following composition are synthesized by the method of cocrystallization of nitrate salts with ultrasonic treatment: La1–xSrxNiO3–δ, La1–xSrxCoO3–δ, and La1–xSrxFe0.7Ni0.3O3–δ (x = 0.30; 0.40). Based on them, ceramic nanomaterials of the given composition with a coherent scattering region (CSR) of ~65–69 nm (1300°С) are obtained. Ceramics fired at 1300°C are single-phase and have a tetragonal and orthorhombic perovskite-type structure in the La2O3‒SrO‒Ni(Co,Fe)2O3–δ system. Solid solutions have mixed electron–ion conductivity with transfer numbers te = 0.98–0.90 and ti = 0.02–0.10. Ceramics with a tetragonal perovskite-type crystal structure exhibit higher electrical conductivity than materials having an orthorhombic perovskite-type crystal structure. According to their electrophysical properties related to the structural features of solid solutions, ceramic materials obtained based on them are promising as solid oxide cathodes for average-temperature fuel cells. [ABSTRACT FROM AUTHOR]

By the joint crystallization of solutions of nitrate salts, fine powders of La1 – xSrxNiO3, La1 ‒xSrx-CoO3, and La1 –xSrxFe0.7Ni0.3O3 (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]