Abstract
A new oxygen-deficient and ordered perovskite-type structure with the formula Sr(Sr0.5Sb0.5)O3−y has been synthesized readily by a solid state reaction in air at 1200°C. The structure of the Sr(Sr0.5Sb0.5)O3−y phase as determined by Rietveld analysis using X-ray diffraction data, corresponds to an ordered perovskite with face-centered cubic symmetry, space group Fm3m (no. 225) and lattice parameters, a=8.3136(3) Å, V=574.602(3) Å3 and Z=8. An important structural feature of Sr(Sr0.5Sb0.5)O3−y is the oxygen deficiency and the displacements of oxygen atoms from their ideal positions toward the Sb5+ cations. This fact leads to an alternating arrangement of larger [SrO6] and smaller [SbO6] octahedra (B-sites), the remaining Sr2+ being in the larger 12-fold coordinated A-sites. The thermal stability of the Sr(Sr0.5Sb0.5)O3−y phase is pointed out, its melting point being 1480°C, and the subsequent quenching giving rise to a glass material.