Synthesis of oxyanion-doped barium strontium cobalt ferrites: Stabilization of the cubic perovskite and enhancement in conductivity

In this paper we demonstrate the successful incorporation of oxyanions (borate, phosphate) into Ba1-ySryCo0.8Fe0.2O3-delta (BSCF) cathode materials. For low levels of dopant, a small enhancement in the conductivity was observed; e.g. 31.6, 34.4 and 35.9S cm(-1) for Ba0.33Sr0.67Co0.8Fe0.2O3-delta, Ba0.33Sr0.67Co0.76Fe0.19B0.05O3-delta and Ba0.33Sr0.67Co0.76Fe0.19P0.05O3-delta, respectively, at 700 degrees C. Most significantly, oxyanion doping was shown to improve the stability of the cubic form of BSCF at intermediate temperatures (especially for P-doping), helping to prevent the transition to a hexagonal cell, and maintaining its excellent electrical properties. The work shows the potential of oxyanion doping strategies to modify the performance of SOFC cathode materials. (C) 2012 Elsevier B.V. All rights reserved.