Topotactic Oxidation of Perovskites to Novel SrMo1-xMxO4-δ (M = Fe and Cr) Deficient Scheelite-Type Oxides.

ABSTRACT: New polycrystalline SrMo1-xMxO4-δ (M = Fe and Cr) scheelite oxides have been prepared by topotactical oxidation, by annealing in air at 500 °C, from precursor perovskites with the stoichiometry SrMo1-xMxO3-δ (M = Fe and Cr). An excellent reversibility between the oxidized Sr(Mo,M)O4-δ scheelite and the reduced Sr(Mo,M)O3-δ perovskite phase accounts for the excellent behavior of the latter as anode material in solid-oxide fuel cells. A characterization by X-ray powder diffraction (XRD) and neutron powder diffraction (NPD) has been carried out to determine the crystal structure features. The scheelite oxides are tetragonal, space group I41/a (No. 88). The Rietveld-refinement from NPD data at room temperature shows evidence of oxygen vacancies in the structure, due to the introduction of Fe3+

SUBMITTER: Cascos V 

PROVIDER: S-EPMC7578960 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature