The formation of the complex manganites LnSr{sub 2}Mn{sub 2}O{sub 7} (Ln = La, Nd, Gd)
- Department of Chemistry, Saint-Petersburg State University, Universitetsky pr., 26, 198504 St.-Petersburg (Russian Federation)
- Solid State Chemistry Laboratory, Zernike Institute for Advanced Materials, University of Groningen, 9747AG Groningen (Netherlands)
Graphical abstract: Display Omitted Highlights: ► Formation of the LnSr{sub 2}Mn{sub 2}O{sub 7} phases proceeds according to two different pathways. ► Cationic composition of the obtained phase depends on the formation pathway. ► Step-by-step synthesis allows obtaining single-phase material. ► Structure and magnetic properties of the single-phase NdSr{sub 2}Mn{sub 2}O{sub 7} were investigated. -- Abstract: The process of formation of the Ruddlesden–Popper phases LnSr{sub 2}Mn{sub 2}O{sub 7} (Ln = La, Nd, Gd) was investigated by means of X-ray diffraction, thermal analysis and microprobe analysis. Two parallel pathways were found for the reaction. The first one includes the formation of the intermediate K{sub 2}NiF{sub 4}-type compound by interaction of Sr{sub 7}Mn{sub 4}O{sub 15} and perovskite-type solid solution (Ln,Sr)MnO{sub 3}, while in the second one the K{sub 2}NiF{sub 4}-type intermediate is formed during the reaction of the same perovskite-type solid solution with the corresponding rare earth oxide. This result gives an explanation for the formation of two phases with slightly different cationic compositions. The kinetics of the reaction was investigated for both mechanisms resulting in determination of their relative contribution to the final composition. Pure NdSr{sub 2}Mn{sub 2}O{sub 7} was obtained using a step-by-step process according to the first mechanism, and the magnetic properties of this phase were investigated.
- OSTI ID:
- 22215663
- Journal Information:
- Materials Research Bulletin, Vol. 47, Issue 12; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
- Country of Publication:
- United States
- Language:
- English
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