Room temperature powder X-ray diffraction (XRD) was performed on a PANalytical Empyrean diffractometer. The obtained XRD patterns were analysed with STOE Win XPOW software in order to determine phase purity, the crystal structure and the cell parameters of the samples. Thermogravimetric analysis (TGA) was performed using a Netzsch STA 449C instrument equipped with Proteus thermal analysis software. The TGA studies were carried out under reducing conditions (5% H2/Ar) from room temperature to 900°C, in order to determine the weight change of the perovskite during the reduction. The microstructure of the samples' surface was analysed using a JEOL JSM-6700 field emission 74 scanning electron microscope (FEG-SEM). The total conductivity of the samples was measured using a conventional four-terminal method. Bar samples were prepared by calcination at 1300°C for 1h. Gold wire contacts were attached to the bars, which then were cured at 850°C for 1h. The conductivity of the samples was measured under a redox cycle at 900°C. Low oxygen partial pressure was achieved by using a continuous flow of 5% H2/Ar.
