X-ray photoelectron spectroscopic studies of Ba0.5Sr0.5Co0.8Fe0.2O3−δ cathode for solid oxide fuel cells

The Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF) cathode for solid oxide fuel cell has been prepared by glycine–nitrate combustion process. Crystal structure and chemical state of BSCF have been studied by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). XRD pattern indicates that a single cubic perovskite phase of BSCF oxide is successfully obtained after calcination at 850 °C for 2 h. XPS results show there exists a little amount of SrCO3 in the surface of BSCF. Co2p spectra indicate that some Co3+ ions have changed into Co4+ ions to maintain the electrical neutrality. O1s spectra present that adsorbed oxygen species appear in the surface BSCF oxide.