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

Abstract

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 SrFe 1− x Co x O 3− δ (0⩽ x⩽0.7), Sr 3Fe 2− y Co y O 7− δ (0⩽ y⩽0.4) and Sr 4Fe 6− z Co z O 13± 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.