Order-disorder transition in the Dy0.2Sr0.8CoO3-delta rare-earth cobalt oxide solid solutions: Structural and thermoelectric properties

By the example of the Dy0.2Sr0.8CoO3-δ compound undergoing an order–disorder phase transition with increasing temperature, we demonstrate a significant dependence of the kinetic properties on the morphology of the internal spatially inhomogeneous structure, which forms in the sample depending on the rate of its transition from the high-temperature disordered cubic phase to the ground tetragonal ordered phase upon cooling. The results of transmission electron microscopy visualization of the spatially inhomogeneous state in the Dy0.2Sr0.8CoO3-δ ceramic samples are presented and compared with the X-ray diffraction data.