Interactions between lanthanum gallate based solid electrolyte and ceria

Possible interactions between La0.9Sr0.1Ga0.8Mg0.2O2.85 and Gd2O3-doped CeO2 (solid electrolyte and anode binding materials, respectively, for solid oxide fuel cells (SOFC)) at 1300°C were studied with diffusion couples and fired powder mixtures. The SrLaGa3O7 compound was detected and its formation was attributed to the diffusion of La2O3 from La0.9Sr0.1Ga0.8Mg0.2O2.85 into Ce1−xLaxO2−x/2 solid solution. As the resistivity of SrLaGa3O7 is rather high, around 1 M·ohm at 800°C, its presence in the solid electrolyte/anode interface could significantly increase the internal resistivity of an SOFC.