Preparation, thermal expansion, chemical compatibility, electrical conductivity and polarization of A2−αA′αMO4 (A = Pr, Sm; A′ = Sr; M = Mn, Ni; α = 0.3, 0.6) as a new cathode for SOFC

A2−αA′αMO4 (A = Pr, Sm, A′ = Sr, M = Ni, Mn) with K2NiF4-type structure were synthesized by solid reaction. Their chemical stability, electrical conductivity and thermal expansion behavior as well as cathodic polarization were investigated in relation to the cathode of SOFC. The results showed that A2−αA′αMO4 exhibited a low reactivity with yttria stabilized zirconia (YSZ) electrolyte. The thermal expansion coefficient (TEC) values were changed with the ionic radius of A. The specific conductivities of the nickelates were higher than those of manganites. While the nickelates showed a lower cathodic polarization in comparison with manganites.