Lanthanum-aluminate-based oxides, (La0.8Sr0.2)(1-y)Al1-xMnxO3-delta (x=0, 0.3, 0.5; y=0 or 0.06) (LSAM), were synthesized and evaluated in detail as potential anode materials for solid oxide fuel cells (SOFCs). The electrical conductivity of LSAM (Mn >= 30 mol%) is dominated by p-type electronic conduction and can be treated as a diluted system of lanthanum manganites, (La,Sr)MnO3. At 810 degrees C, the electrical conductivity of (La0.8Sr0.2)(0.94)Al0.5Mn0. 5O3-delta (LSAM8255b) reaches 12 S/cm in air and 2.7 S/cm in humidified Ar/4% H, (p(O-2)approximate to 10(-18) bar). The thermal expansion coefficients of LSAM8255a and LSAM8255b match YSZ very well and no chemical reaction was observed between these two perovskite materials and YSZ up to at least 1400 degrees C. Fairly good electrochemical performance was observed for an LSAM8255b-YSZ composite anode. At 850 degrees C, the polarization resistances are only 0.34 and 0.50 Omega cm 2 in wet (similar to 3% H2O) Ar/20% H-2 and wet Ar/20% CH4, respectively. In addition, an exposure to Ar/20% CH4/3% H2O for 35 h did not cause any apparent carbon deposition on the electrode. However, the chemical stability of LSAM8255a and LSAM8255b in a typical anode environment under open circuit conditions does not seem sufficient, leading to performance degradation with time in wet Ar/20% H, or wet Ar/20% CH4. Furthermore, relatively large chemical expansion (0.3-0.5%) was observed when the atmosphere was switched from air to wet Ar/4% H?, which might cause intolerable stress on the thin film electrolyte layer for a large-area anode-supported planar SOFC, but which might be tolerable for small geometries or electrolyte-supported SOFCs. (c) 2006 Elsevier B.V. All rights reserved.