Structural investigation of anion-deficient manganites La0.7Sr0.3MnO3 − δ

The crystal structure of the anion-deficient manganites La0.7Sr0.3MnO3 − δ (δ = 0, 0.10, 0.15, 0.20) is investigated using high-resolution neutron diffraction. At room temperature, the crystal structure of the stoichiometric manganite La0.7Sr0.3MnO3 and the anion-deficient manganite La0.7Sr0.3MnO2.9 is satisfactorily described in rhombohedral space group R\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$\bar 3$$ \end{document}c. The anion-deficient manganite La0.7Sr0.3MnO2.85 is characterized by two perovskite phases with space groups R\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$\bar 3$$ \end{document}c and 14/mcm. The crystal structure of the La0.7Sr0.3MnO2.8 manganite corresponds to the structure of a perovskite phase with space group I4/mcm. It is established that the phase separation in the crystal structure of the La0.7Sr0.3MnO3 − δ manganites at a temperature of 293 K is associated with a nonuniform distribution of oxygen vacancies.