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Charge Disproportionation and Magnetoresistivity in a Double Perovskite with Alternate Fe 4+ (d 4 ) and Mn 4+ (d 3 ) Layers
Author(s) -
Ganesanpotti Subodh,
Tassel Cédric,
Hayashi Naoaki,
Goto Yoshihiro,
Bouilly Guillaume,
Yajima Takeshi,
Kobayashi Yoji,
Kageyama Hiroshi
Publication year - 2014
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201402009
Subject(s) - chemistry , disproportionation , ferrimagnetism , perovskite (structure) , crystallography , manganese , mössbauer spectroscopy , brownmillerite , space group , stoichiometry , inorganic chemistry , x ray crystallography , magnetization , catalysis , diffraction , biochemistry , physics , organic chemistry , quantum mechanics , magnetic field , optics
An oxygen‐stoichiometric, B‐site‐ordered perovskite Ca 2 Fe 1.1 Mn 0.9 O 6 (CFMO) with alternate stacking of Fe and Mn layers was obtained through topochemical oxidation of the corresponding brownmillerite phase under high pressure in the presence of KClO 4 . The structure crystallizes in the P 2 1 / m space group with a doubling of the cell along all three crystallographic axes. Mössbauer spectroscopy, susceptibility, and resistivity measurements suggest ferromagnetic interactions between Fe 4+ (d 4 ) and Mn 4+ (d 3 ) along [001] through a double‐exchange mechanism, a situation similar to half‐doped manganese perovskite oxides. Upon cooling, CFMO exhibits a ferrimagnetic transition below T c = 90 K, likely accompanied by a charge disproportionation of the iron site, 2Fe 4+ → Fe 3+ + Fe 5+ . A reasonably good magnetoresistivity of 27 % was observed below T c .