Phase equilibria and crystal structure of the complex oxides in the Sr–Fe–Co–O system

Phase relations in the Sr–Fe–Co–O system have been investigated at 1100 °C in air by X-ray powder diffraction on quenched samples. Solid solutions of the form SrFe1−xCoxO3−δ (0⩽x⩽0.7), Sr3Fe2−yCoyO7−δ (0⩽y⩽0.4) and Sr4Fe6−zCozO13±δ (0⩽z⩽1.6) were prepared by solid-state reaction and by the sol–gel method. The structural parameters of single-phase samples were refined by the Rietveld profile method. The variation of the lattice parameters with composition has been determined for each solid solution and a cross-section of the phase diagram at 1100 °C in air for the entire Sr–Fe–Co–O system has been constructed.