Effect of Fe Content on the Structure and Properties of Sr-Fe-Co Oxides

Abstract

SrFexCo0.5O3-δ (x=0.5, 0.75, 1.0, 1.25) powders have been synthesized by the solid state reaction process. The effect of Fe content on the microstructure and properties of the SrFexCo0.5O3-δ powders were investigated in detail by X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermo-gravimetric analysis and differential scanning calorimeters (TGA/DSC). XRD results reveal that the phases of the SrFexCo0.5Oδ powders are dependent on the content of Fe. X-ray diffraction. SEM images show that the obtained powders have similar morphology with particle structure and uniform size distribution. The phase transition from ordered brownmillerite structure to disorder perovskite structure is strongly dependent on the content of Fe by the TGA/DSC analysis of the SrFexCo0.5O3-δ powders. Phase transition temperature increases from 770°C to 800°C with the x value in the SrFexCo0.5O3-δ increasing to 1.0. But the phase of the SrFe1.25Co0.5O3-δ powder maintains unchanged behaving good phase stability and chemistry stability.