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Structural Determination and Imaging of Charge Ordering and Oxygen Vacancies of the Multifunctional Oxides REBaMn 2 O 6‐ χ (RE = Gd, Tb)
Author(s) -
ÁvilaBrande David,
King Graham,
UronesGarrote Esteban,
Llobet Anna,
GarcíaMartín Susana
Publication year - 2014
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201303564
Subject(s) - materials science , oxygen , charge ordering , neutron diffraction , perovskite (structure) , transmission electron microscopy , phase (matter) , crystallography , stoichiometry , electron diffraction , crystal structure , ionic bonding , diffraction , analytical chemistry (journal) , ion , charge (physics) , chemistry , nanotechnology , physics , optics , chromatography , organic chemistry , quantum mechanics
Charge ordering and oxygen vacancy ordering are revealed in REBaMn 2 O 6‐ δ (RE = Gd, Tb) oxides with perovskite‐related structures. Electron diffraction and transmission electron microscopy results indicate a modulation of the crystal structure. The average oxidation state of Mn and the oxygen stoichiometry are determined by means of electron energy‐loss spectroscopy, giving a REBaMn 2 O 5.75 general formula. A 1:3 Mn 4+ :Mn 3+ charge ordering model is confirmed by neutron powder diffraction, and oxygen vacancies‐Mn 3+ association is suggested by pair distribution function analysis. Direct imaging of the oxygen sublattice is obtained by phase image reconstruction. Location of the oxygen vacancies in the anion sublattice is achieved by analysis of the intensity of the averaged phase image. Both ionic conduction and multiferroic behavior are predicted from the crystal structures of these oxides.