Chemical and thermomechanical compatibility between neodymium manganites and electrolytes based on ceria

The goal of this work was to study the thermal expansion behaviour of NdMe0.5Mn0.5O3 (Me = Ni, Co) solid solutions and to establish the phase relations between them, used as cathodes, and two electrolytes based on Ce0.9Gd0.1O1.95. The electrolyte was doped with 1.0 wt% Bi2O3 in order to improve the final densification.Intimate mixtures of the cathode and electrolyte powders were reacted at several temperatures for studying the possible reaction products. Cathode–electrolyte pairs were obtained by isostatic pressing of constituent powders and subsequent sintering in the temperature range 1350–1400 °C for 2 h to observe the interphase compatibility. The sintering conditions were optimized to obtain highly densified electrolytes and well-developed cathode–electrolyte interfaces. Scanning electron microscopy observation with EDAX analysis was performed in cathode–electrolyte interfacial regions in order to characterize the obtained microstructures and to determine possible cation interdiffusion between the cathode and the electrolyte.The nickel-doped manganite, NdNi0.5Mn0.5O3, is chemically and thermo-mechanically compatible with both electrolytes without formation of new phases up to 1400 °C even during long treatment times. On the other hand, NdCo0.5Mn0.5O3 perovskite not had a good behaviour with none of the electrolytes.