Structure, nonstoichiometry, sintering and oxygen permeability of perovskite SrCo_1-2x(Fe,Nb)_xO_3-δ (x = 0.05, 0.10) oxides

The novel Fe/Nb co-substituted SrCo_1-2x(Fe,Nb)_xO _3-δ (x = 0.05, 0.10) oxides have been synthesized and characterized by X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetry (TG), and scanning electron microscopy (SEM). The XRD and DSC results demonstrate that the structural stability of the Fe/Nb co-substituted samples x = 0.05, 0.10 is improved greatly compared to the sample x = 0.00. The Fe/Nb co-doping in the SrCoO_3-δ oxide results in the improved structural stability of the SrCo_1-2x(Fe,Nb) _xO_3-δ (x = 0.05, 0.10) oxides. The nonstoichiometric and sintering properties were investigated by TG and SEM, and the oxygen permeation fluxes were measured at 800-950 °C for the sample x = 0.10. The improved oxygen permeability of the ceramic SrCo_1-2x(Fe,Nb) _xO_3-δ (x = 0.10) membrane compared to the (Ba _0.5Sr_0.5)(Co_0.8Fe_0.2)O _3-δ and SrCo_0.8Fe_0.2O_3-δ membranes, was observed under an air/He oxygen partial pressure gradient at 800-950 °C.