In order to develop a cathode that can be used in intermediate temperature solid oxide fuel cells (ITSOFC), the double perovskite material GdBaCo2O5, has been prepared and its electrode performance investigated at temperatures below 700 degrees C by AC impedance spectroscopy. Preliminary results show that the ASRs of GdBaCo2O5+x cathode materials are as low as 0.53 Omega cm(2) at 645 degrees C. This encouraging data identifies GdBaCo2O5+x as a potential cathode material for ITSOFCs. (c) 2006 Elsevier B.V. All rights reserved.