Room temperature mechanosynthesis of the La{sub 1-x}Sr{sub x}MnO{sub 3{+-}{delta}} (0{<=}x{<=}1) system and microstructural study
- Instituto de Ciencia de Materiales de Sevilla, Centro mixto CSIC-US, Av. Americo Vespucio 49, 41092 Seville (Spain)
Monophase nanocrystalline powders belonging to the La{sub 1-x}Sr{sub x}MnO{sub 3{+-}{delta}} system (0{<=}x{<=}1) with a perovskite structure have been obtained by mechanochemistry synthesis using a planetary ball milling equipment from La{sub 2}O{sub 3}, SrO, and Mn{sub 2}O{sub 3} mixtures. The solid state reaction was complete after one hour of milling treatment. For all the compositional range, the diffraction domain was very small and the structure appeared as a pseudo cubic perovskite. After annealing at 1100 Degree-Sign C under static air, the symmetry evolution due to the La substitution by Sr was analyzed by X-ray and electron diffraction. Samples with x=0, 0.25, 0.5, and 0.75 were assigned to R-3c space group (1 6 7) in the rhombohedral system and perovskite structure. However, the symmetry of the last term of the system (x=1), SrMnO{sub 3{+-}{delta}} sample, changed to P6{sub 3}/mmc space group (1 9 4) in the hexagonal system. The terms with x=0.8, 0.85, and 0.9 presented mainly rhombohedral symmetry. - Graphical abstract: SEM micrographs corresponding to milled (M) and Heated (H) samples: LaMnO{sub 3{+-}{delta}}(M1 and H1) La{sub 0.75}Sr{sub 0.25}MnO{sub 3{+-}{delta}}(M2 and H2,) and SrMnO{sub 3{+-}{delta}}(M8 and H8). Highlights: Black-Right-Pointing-Pointer Synthesis of La{sub 1-x}Sr{sub x}MnO{sub 3{+-}{delta}} by mechanochemistry, a very simple and scalable method. Black-Right-Pointing-Pointer System with rhombohedral perovskite structure forming a solid solution till x=0.9. Black-Right-Pointing-Pointer Powder material with nanometer character that reduces the sinterization temperature. Black-Right-Pointing-Pointer Appropriate Microstructure for cathode electrodes to built SOFCs.
- OSTI ID:
- 22012082
- Journal Information:
- Journal of Solid State Chemistry, Vol. . 188; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
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