ИСТИНА

Novel La1-yCayFe0.5+x(Mg,Mo)0.5-xO3- perovskites were synthesized in air at 1300oC, 72h. For La1-yCayFe0.5(Mg0.2625Mo0.2375)O3-, y=0.45-0.8 and La1-yCayFe0.6Mg0.175Mo0.225O3-, y=0.5-0.8 combined X-ray powder and electron diffraction studies reveal the formation of the orthorhombic GdFeO3-type perovskite phases. X-ray powder and electron diffraction studies reveal the formation of the orthorhombic GdFeO3-type perovskite phases for La1-yCayFe0.5(Mg0.2625Mo0.2375)O3-, y=0.45-0.8 and La1-yCayFe0.6Mg0.175Mo0.225O3-, y=0.5-0.8. Among various oxides perovskites with 3d-metal cations like Ti, Cr, Mn, Fe have been considered as prospective electrode materials for symmetrical SOFC. This is mainly because in contrast to perovskites with late 3d-metal cations such as Co, Ni and Cu they demonstrate stability in reducing atmosphere at high temperature. It should be mentioned that double perovskites with Mo in B-position have also been considered as promising electrode materials in symmetrical SOFC since they combine stability in both oxidizing and reducing environment with very high electronic conductivity. High-temperature electrical conductivity measurements in the air and Ar/H2 show that highest conductivity is observed for Fe- and Ca-rich compositions. All samples demonstrate temperature activated electrical conductivity below 10 S/cm at 900oC. The highest electrical conductivity is observed for La0.3Ca0.7Fe0.6Mo0.225Mg0.175O3- sample with electrical conductivity of 6.1 S/cm at 900oC. Combination of the obtained data allows to select La0.3Ca0.7Fe0.6Mo0.225Mg0.175O3- perovskite as promising electrode material for symmetrical solid oxide fuel cells.