Synthesis and Structure Determination of Ferromagnetic Semiconductors LaAMnSnO6 (A = Sr Ba)
LaAMnSnO{sub 6} (A = Sr, Ba) have been synthesized by high temperature solid-state reactions under dynamic 1% H{sub 2}/Ar flow. Rietveld refinements on room temperature powder X-ray diffraction data indicate that LaSrMnSnO{sub 6} crystallizes in the GdFeO{sub 3}-structure, with space group Pnma and, combined with transmission electron microscopy, LaBaMnSnO{sub 6} in Imma. Both space groups are common in disordered double-perovskites. The Mn{sup 3+} and Sn{sup 4+} ions whose valence states were confirmed by X-ray absorption spectroscopy, are completely disordered over the B-sites and the BO{sub 6} octahedra are slightly distorted. LaAMnSnO{sub 6} are ferromagnetic semiconductors with a T{sub C} = 83 K for the Sr- and 66 K for the Ba-compound. The title compounds, together with the previously reported LaCaMnSnO{sub 6} provide an interesting example of progression from Pnma to Imma as the tolerance factor increases. An analysis of the relationship between space group and tolerance factor for the series LaAMnMO{sub 6} (A = Ca, Sr, Ba; M = Sn, Ru) provides a better understanding of the symmetry determination for double perovskites.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- Sponsoring Organization:
- USDOE SC OFFICE OF SCIENCE (SC)
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 1042163
- Report Number(s):
- BNL-97841-2012-JA; JMACEP; TRN: US201212%%574
- Journal Information:
- Journal of Materials Chemistry, Vol. 21; ISSN 0959-9428
- Country of Publication:
- United States
- Language:
- English
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