The effect of MgO addition on thermomechanical and electrical transport properties of La 0.5 Sr 0.5 FeO 3-δ perovskite-like ferrite

Composite materials La0.5Sr0.5FeO3-delta/MgO (LSF/MgO) were synthesized by glycine-nitrate route. Phase composition was checked using X-Ray diffraction (XRD) method. Composite microstructure was confirmed by microscopic methods. MgO addition was found to facilitate sintering of the composites. Thermal expansion studies have shown that LSF/MgO materials tend to possess lower thermal expansion coefficient (TEC) with increasing of MgO addition. Measuring electrical conductivity of the composites has shown the increase of MgO content leads to non-monotonous decrease of samples' conductance. An effective medium theory (EMT) is utilized to explain the observed feature. The obtained model parameters are used to evaluate hydrogen production rate from 1 cm(2) of ceramic membrane's surface in water splitting coupled to partial oxidation of methane (WS-POM) process. It is suggested that the addition of MgO in the amount of 3-6 mass % to LSF can be a perspective tool for improving WS-POM efficiency.