Synthesis, phase stability and electrical conductivity of Sr2MgMoO6−δ anode

A freeze-drying precursor method has been used to prepare polycrystalline materials of the new SOFC anode, Sr2MgMoO6−δ. The optimal synthesis conditions were studied in order to avoid secondary phase segregations. These materials were characterised by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermal analysis (TG/DTA) and scanning electron microscopy (SEM). The as-synthesised polycrystalline powders showed homogeneous particle size distribution in the submicrometric range. The stability studies demonstrated that this phase is stable up to 1200 °C under 5% H2-Ar. In addition, impedance spectroscopy was used to determine the conductivity of ceramic pellets prepared under oxidising and reducing atmosphere. Samples sintered in reducing atmosphere exhibit higher conductivity values than those prepared in air.