Synthesis and electrical characterization of the ceramic anode La 1-x Srx Mn0.5 Cr0.5 O3

Abstract

The synthesis and electrical characterization of La1-x Srx Mn0.5 Cr0.5 O3 compounds are reported. These compounds, with perovskite structure, have been pointed out as a promising alternative for the nickel-based cermet anode of solid oxide fuel cells. Polycrystalline samples, with x=0.3, 0.4, and 0.5, were prepared by the citrate technique. The crystalline phase and the chemical compatibility with zirconia-based electrolytes were studied by X-ray diffraction analyses. The electrical properties were studied by four-probe dc electrical conductivity (T) measurements during redox cycles under both oxidizing and reducing atmospheres. The main results show that the (T) has a thermally activated behavior, and increasing Sr content increases (T). Compounds with x=0.3 exhibited no appreciable chemical reaction with the stabilized zirconia electrolyte after heat-treatment at high temperature. The (T) measurements evidenced the redox stability of the ceramic anode. However, some degradation of the (T) was observed on samples thermally treated at 1000°C under pure hydrogen.