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Author Brázda, Petr ♦ Palatinus, Lukáš ♦ Klementová, Mariana ♦ Buršík, Josef ♦ Knížek, Karel
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY ♦ CATIONS ♦ COBALT OXIDES ♦ CRYSTALS ♦ ELECTRON DIFFRACTION ♦ LANTHANUM COMPOUNDS ♦ LANTHANUM IONS ♦ MAPPING ♦ POWDERS ♦ TRANSMISSION ELECTRON MICROSCOPY ♦ TWINNING ♦ TWO-DIMENSIONAL SYSTEMS ♦ X-RAY DIFFRACTION
Abstract We have used electron diffraction tomography and powder X-ray diffraction to elucidate the structural properties of layered cobaltate γ-La{sub 0.30}CoO{sub 2}. The structure consists of hexagonal sheets of edge-sharing CoO{sub 6} octahedra interleaved by lanthanum monolayers. The La{sup 3+} cations occupy only one third of available P2 sites, forming a 2-dimensional a√3×a√3 superstructure in a–b plane. The results show that there exists no order in the mutual relative shift between the neighbouring La interlayers within the a–b plane. This is manifested in the observed monotonous decrease of the diffracted intensity of the superstructure diffractions along c{sup ⁎} in both X-ray and electron diffraction data. The observed lack of stacking order differentiates the La{sub x}CoO{sub 2} from its Ca and Sr analogues where at least a partial stacking order of the cationic interlayers is manifested in experimental data published in literature. - Highlights: • We use electron diffraction tomography for reciprocal space mapping of La{sub 0.30}CoO{sub 2}. • We observed a complete disorder of the stacking of Lanthanum interlayers. • Co{sub 3}O{sub 4} intergrown with La{sub 0.30}CoO{sub 2} crystals brings about fake superstructure diffractions. • Twinning of Co{sub 3}O{sub 4} enhances the problem of fake superstructure diffractions.
ISSN 00224596
Educational Use Research
Learning Resource Type Article
Publisher Date 2015-07-15
Publisher Place United States
Journal Journal of Solid State Chemistry
Volume Number 227


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