6533b825fe1ef96bd12826a2

RESEARCH PRODUCT

Short- and long-range order in La1−xSrxCoO3 and La1−xBaxCoO3

V.g. SimkinD. KarpinskyA. SazonovA. SazonovJuris PuransI. O. TroyanchukV. V. SikolenkoS. I. TiutiunnikovD. ZajacE. A. EfimovaE. WelterAlexei KuzminV. V. Efimov

subject

X-ray absorption spectroscopyAbsorption spectroscopychemistry.chemical_elementGeneral ChemistryCrystal structureCondensed Matter PhysicsOxygenIonCrystalCrystallographyAmplitudechemistryPerpendicularGeneral Materials Science

description

Abstract The short- and long-range order correlations of the crystal structure in the distorted perovskites La 1− x Sr x CoO 3 and La 1− x Ba x CoO 3 (0.0⩽ x ⩽0.5) have been studied by the neutron powder diffraction (NPD) and the Co K-edge X-ray absorption spectroscopy (XAS) measurements. The results of XAS and NPD indicate a local distortion around the Co 3+ ions in LaCoO 3 at room temperature. The substitution of the La 3+ ions by the Sr 2+ (Ba 2+ ) ions leads to a gradual increase of the Co–O–Co angle and is accompanied by an increase of the mean square relative displacement (MSRD) of the Co–O bond. These results correlate with an increase of the oxygen amplitude vibration in the direction perpendicular to the Co–O bond. The possible explanation of the observed changes of the crystal and electronic structures in the above-mentioned cobaltites is discussed.

yearjournalcountryeditionlanguage
2008-09-01Journal of Physics and Chemistry of Solids
https://doi.org/10.1016/j.jpcs.2008.03.040