Structure and microstructure of the high pressure synthesised misfit layer compound [Sr{sub 2}O{sub 2}][CrO{sub 2}]{sub 1.85}

The strontium chromium oxide [Sr{sub 2}O{sub 2}][CrO{sub 2}]{sub 1.85} misfit layer compound has been synthesised at high-pressure and high-temperature conditions. Electron diffraction patterns and high-resolution transmission electron microscopy images along [001] show the misfit character of the d...

Full description

Saved in:
Bibliographic Details
Published in:Journal of solid state chemistry 2008-08, Vol.181 (8)
Main Authors: Castillo-Martinez, E., Schoenleber, A., Smaalen, S. van, Arevalo-Lopez, A.M., Alario-Franco, M.A.
Format: Article
Language:English
Subjects:
ANISOTROPY
CHROMIUM OXIDES
CRYSTAL DEFECTS
ELECTRON DIFFRACTION
INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY
LATTICE PARAMETERS
LAYERS
LEAD SULFIDES
MICROSTRUCTURE
MONOCRYSTALS
ORTHORHOMBIC LATTICES
STRONTIUM OXIDES
TITANIUM SULFIDES
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The strontium chromium oxide [Sr{sub 2}O{sub 2}][CrO{sub 2}]{sub 1.85} misfit layer compound has been synthesised at high-pressure and high-temperature conditions. Electron diffraction patterns and high-resolution transmission electron microscopy images along [001] show the misfit character of the different layers composing the structure with a supercell along the incommensurate parameter b{approx}7b{sub 1}{approx}13b{sub 2}. The modulated crystal structure has been refined within the superspace formalism against single-crystal X-ray diffraction data, employing the (3+1)-dimensional superspace group C'nmb(0{sigma}{sub 2}0)0 0 s. The compound has a composite structure with lattice parameters a{sub 1}=5.182(1) A, b{sub 1}=5.411(1) A, c{sub 1}=18.194(3) A for the first, SrO, subsystem and the same a and c, but with b{sub 2}=2.925(1) A for the second, CrO{sub 2}, subsystem. The layer stacking is similar to that of orthorhombic PbS(TiS{sub 2}){sub 1.18}, but with a much stronger intersubsytem bonding in the case of the oxide. The intersubsystem lattice mismatch is mainly handled by displacement modulations of the Sr atoms, correlated with modulations of the valence, the coordination and the anisotropic displacement parameters. - Graphical abstract: A strontium chromium oxide, [Sr{sub 2}O{sub 2}][CrO{sub 2}]{sub 1.85}, with an orthorhombic misfit layer structure has been synthesised under high pressure. Mainly modulations on the Sr position, ADPs and coordination save the subsystems lattice mismatch.
ISSN:0022-4596
1095-726X
DOI:10.1016/j.jssc.2008.03.033