The Sr2.4Dy0.6Co2O7-δ Ruddlesden‒Popper Phase: Structural, thermoelectric, and magnetic properties

―A new anion-deficient Sr2.4Dy0.6Co2O7‒δ (δ = 0.33–1.1) perovskite phase with a structure of the A3B2O7 Raddlesden‒Popper homologous series has been obtained by the solid-state synthesis in the reducing/oxidizing atmosphere and its structural characterization has been performed by the Rietveld refinement of the X-ray powder diffraction data. It has been stablished that the Sr2.4Dy0.6Co2O7‒δ compound (sp. gr. I4/mmm) has parameters of a = b = 3.8526(1) and c = 19.9431(7) A in the reduced form (δ = 1.1) and a = b = 3.8086(1) and c = 19.9190(6) A in the oxidized form (δ ≈ 0.33) and oxygen vacancies occupy mainly the sites linking CoO5 polyhedra inside two perovskite layers. It has been established using differential scanning calorimetry and thermogravimetry that, at T