Chemical analysis at atomic resolution of isolated extended defects in an oxygen-deficient, complex manganese perovskite

M Luisa Ruiz-González; Raquel Cortés-Gil; Almudena Torres-Pardo; Daniel González-Merchante; José M Alonso; José M González-Calbet

doi:10.1002/chem.201303895

Chemical analysis at atomic resolution of isolated extended defects in an oxygen-deficient, complex manganese perovskite

Chemistry. 2014 Jan 27;20(5):1237-41. doi: 10.1002/chem.201303895. Epub 2013 Dec 27.

Authors

M Luisa Ruiz-González¹, Raquel Cortés-Gil, Almudena Torres-Pardo, Daniel González-Merchante, José M Alonso, José M González-Calbet

Affiliation

¹ Departamento de Química Inorgánica, Facultad de Químicas, Universidad Complutense (UCM), CEI Moncloa, 28040 Madrid (Spain).

PMID: 24375704
DOI: 10.1002/chem.201303895

Abstract

A general approach to the structural and analytical characterization of complex bulk oxides that exploits the advantage of the atomic spatial resolution and the analytical capability of aberration-corrected microscopy is described. The combined use of imaging and spectroscopic techniques becomes necessary to the complete characterization of the oxygen-deficient colossal magnetoresistant La(0.56)Sr(0.44)MnO(2.5)-related perovskite. In this compound, the formation of isolated (La/Sr)O and MnO rock-salt-type planar defects are identified from atomically resolved High Angle Annular Dark Field (HAADF) images. The location of the oxygen atomic columns from Annular Bright Field (ABF) images indicates edge-sharing MnO6 octahedra in the MnO planes and the study performed by Electron Energy Loss Spectroscopy (EELS) reveals different Mn oxidation states derived from the corner- or edge-sharing MnO6 octahedra environment.

Keywords: aberration-corrected microscopy; atomic-resolution STEM; colossal magnetoresistant oxides; electron energy loss spectroscopy (EELS); extended defects.