Crystal structure of La{sub 0.4}Sr{sub 0.6}CoO{sub 2.71} investigated by TEM and XRD

Journal Article · Sat Nov 15 00:00:00 EST 2008 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2008.06.058· OSTI ID:21212091

Gspan, C ^[1]; Grogger, W ^[1]; Bitschnau, B ^[2]; Bucher, E; Sitte, W ^[3]; Hofer, F ^[1]

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1. Institute for Electron Microscopy and Fine Structure Research, Graz University of Technology, Steyrergasse 17, A-8010 Graz (Austria)
2. Institute of Physical and Theoretical Chemistry, Graz University of Technology, Technikerstrasse 4, A-8010 Graz (Austria)
3. Department of General, Analytical and Physical Chemistry, University of Leoben, Franz-Josef-Strasse 18, A-8700 Leoben (Austria)

The structure of the oxygen-deficient perovskite La{sub 0.4}Sr{sub 0.6}CoO{sub 3-{delta}} ({delta}=0.29) was investigated by transmission electron microscopy (TEM) and X-ray powder diffraction (XRD). Domains between 50 and 250 nm in size were observed in the electron microscope. Weak superstructure reflections were found with both X-ray and electron diffraction. Investigations of these superstructure reflections by selected area electron diffraction (SAED) and convergent beam electron diffraction (CBED) showed that the domains in a crystal are orientated in a 90 deg. relationship. High-resolution transmission electron microscopy (HRTEM) images from the domain boundary also revealed a 90 deg. orientation dependency. Using the symmetry of CBED patterns, the point group 4/mmm was determined. By comparing reflections from the SAED pattern with possible reflections, the space group I4/mmm (No. 139) could be isolated and finally the crystal structure was refined by Rietveld refinement. - Graphical abstract: Two adjacent domains show different orientation of the c-axis of the tetragonal unit cell in the according convergent beam electron diffraction patterns.

• OSTI ID: 21212091
• Journal Information: Journal of Solid State Chemistry, Vol. 181, Issue 11; Other Information: DOI: 10.1016/j.jssc.2008.06.058; PII: S0022-4596(08)00351-4; Copyright (c) 2008 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
COBALT COMPOUNDS
ELECTRON BEAMS
ELECTRON DIFFRACTION
ELECTRON MICROSCOPES
LANTHANUM COMPOUNDS
OXIDES
PEROVSKITE
RESOLUTION
SPACE GROUPS
STRONTIUM COMPOUNDS
TETRAGONAL LATTICES
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION