Crystallographic and magnetic characterisation of the brownmillerite Sr{sub 2}Co{sub 2}O{sub 5}
- School of Chemistry, University of Birmingham, Birmingham B15 2TT (United Kingdom)
- EMAT, University of Antwerp Groenenborgerlaan 171, B-2020 Antwerp (Belgium)
Sr{sub 2}Co{sub 2}O{sub 5} with the perovskite-related brownmillerite structure has been synthesised via quenching, with the orthorhombic unit cell parameters a=5.4639(3) A, b=15.6486(8) A and c=5.5667(3) A based on refinement of neutron powder diffraction data collected at 4 K. Electron microscopy revealed L-R-L-R-intralayer ordering of chain orientations, which require a doubling of the unit cell along the c-parameter, consistent with the assignment of the space group Pcmb. However, on the length scale pertinent to NPD, no long-range order is observed and the disordered space group Imma appears more appropriate. The magnetic structure corresponds to G-type order with a moment of 3.00(4) {mu}{sub B} directed along [1 0 0]. -- Graphical abstract: Possible ordering of the tetrahedral chains in Sr{sub 2}Co{sub 2}O{sub 5}. Display Omitted Research highlights: {yields} Sr{sub 2}Co{sub 2}O{sub 5} has alternating (L and R) chains in a given tetrahedral layer. {yields} Order between layers is limited. {yields} NPD shows no evidence for the doubled unit cell-averaged structure. {yields} The length scale for a given technique is critical in considering space group.
- OSTI ID:
- 21494228
- Journal Information:
- Journal of Solid State Chemistry, Vol. 184, Issue 3; Other Information: DOI: 10.1016/j.jssc.2011.01.026; PII: S0022-4596(11)00027-2; Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
COBALT COMPOUNDS
CRYSTALLOGRAPHY
ELECTRON DIFFRACTION
ELECTRON MICROSCOPY
ION MICROPROBE ANALYSIS
LAYERS
NEUTRON DIFFRACTION
ORIENTATION
ORTHORHOMBIC LATTICES
OXIDES
PEROVSKITE
QUENCHING
SPACE GROUPS
STRONTIUM COMPOUNDS
TETRAGONAL LATTICES
ALKALINE EARTH METAL COMPOUNDS
CHALCOGENIDES
CHEMICAL ANALYSIS
COHERENT SCATTERING
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DIFFRACTION
MICROANALYSIS
MICROSCOPY
MINERALS
NONDESTRUCTIVE ANALYSIS
OXIDE MINERALS
OXYGEN COMPOUNDS
PEROVSKITES
SCATTERING
SYMMETRY GROUPS
TRANSITION ELEMENT COMPOUNDS