Double-perovskites YBaCo2-chi Fe chi O5+delta (YBCF, chi = 0.0, 0.2, 0.4 and 0.6) are synthesized with a solid-state reaction and are assessed as potential cathode materials for utilization in intermediate-temperature solid oxide fuel cells (IT-SOFCs) on the La0.9Sr0.1Ga0.8Mg0.115Co0.085O2.85 (LSGMC) electrolyte. The YBCF materials exhibit chemical compatibility with the LSGMC electrolyte up to a temperature of 950 degrees C. The conductivity of the YBCF samples decreases with increasing Fe content, and the maximum conductivity of YBCF is 315 S cm(-1) at 325 degrees C for the chi = 0.0 sample. A semiconductor-metal transition is observed at about 300-400 degrees C. The thermal expansion coefficient of the YBCF samples increases from 16.3 to 18.0 x 10(-6) K-1 in air at temperatures between 30 and 900 degrees C with increase in Fe content. The area-specific resistances of YBCF cathodes at chi = 0.0, 0.2 and 0.4 on the LSGMC electrolyte are 0.11, 0.13 and 0.15 Omega cm(2) at a temperature of 700 degrees C, respectively. The maximum power densities of the single cells fabricated with the LSGMC electrolyte, Ce0.8Sm0.2O1.9 (SDC) interlayer, NiO/SDC anode and YBCF cathodes at chi = 0.0, 0.2 and 0.4 reach 873,768 and 706 mW cm(-2), respectively. This study suggests that the double-perovskites YBCF (0 <= chi <= 0.4) can be potential candidates for utilization as IT-SOFC cathodes. (c) 2010 Elsevier B.V. All rights reserved.