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Ferromagnetism in a New Manganese‐Related Brownmillerite: La 0.5 Sr 0.5 MnO 2.5
Author(s) -
CortésGil Raquel,
RuizGonzález M. Luisa,
Alonso José M.,
ValletRegí María,
Hernando Antonio,
GonzálezCalbet José M.
Publication year - 2007
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200601279
Subject(s) - brownmillerite , isostructural , manganese , crystallography , ferromagnetism , materials science , microstructure , crystal structure , condensed matter physics , chemistry , perovskite (structure) , metallurgy , physics
The topotactic reduction of La 0.5 Sr 0.5 MnO 3 leads to ordering of the anionic vacancies in the La 0.5 Sr 0.5 MnO 2.5 composition. The isolated material, which is isostructural with Sr 2 Fe 2 O 5 , crystallises in the brownmillerite structural type with unit cell parameters a =0.54117(3), b =1.67608(12), c =0.54004(3) nm and space group Ibm 2. Its microstructural characterisation by means of electron diffraction and high‐resolution electron microscopy suggests a complex microstructure arising from the coherent intergrowth of different brownmillerite‐type domains that show short‐range ordering at the A sub‐lattice. The layer structure of La 0.5 Sr 0.5 MnO 2.5 leads to a double magnetic behaviour where a ferromagnetic two‐dimensional component is present.