A study of a new incommensurate phase in the system SrMn sub 1-x Co sub x O sub 3-y

Journal Article · Tue Aug 01 04:00:00 EDT 1989 · Journal of Solid State Chemistry; (USA)

DOI:https://doi.org/10.1016/0022-4596(89)90009-1· OSTI ID:6986756

Battle, P D; Gibb, T C ^[1]; Strange, R ^[2]

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1. The University, Leeds (England)
2. Daresbury Lab., Warrington (England)

The oxygen-deficient system SrMn{sub 1-x}Co{sub x}O{sub 3-y} (0 {le} {times} {le} 1) has been studied by X-ray and neutron powder diffraction, magnetic susceptibility, {sup 57}Fe Moessbauer spectroscopy, and EXAFS techniques. Three new phases have been obtained, the most significant being an incommensurate phase for 0.40 {le} {times} {le} 0.55 which is believed to be closely related to the family of perovskite structures with hexagonal symmetry. However, the EXAFS data show the existence of some as yet unidentified structural features which are not found in perovskites, for example a Co-Co distance of {approx} 2.8 {Angstrom}. The Mn cations occupy an environment which is significantly different from that of the Co cations. At high cobalt content (x {approx} 0.8) and high temperatures the system adopts a pseudocubic perovskite structure, with corner-shared polyhedra, which transforms on slow cooling to a poorly defined hexagonal phase containing face- and edge-shared polyhedra, similar to H-Sr{sub 2}Co{sub 2}O{sub 5+z}. There is evidence to suggest that these hexagonal phases may also be incommensurate.

• OSTI ID: 6986756
• Journal Information: Journal of Solid State Chemistry; (USA), Journal Name: Journal of Solid State Chemistry; (USA) Vol. 81:2; ISSN 0022-4596; ISSN JSSCB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360000* -- Materials
360100 -- Metals & Alloys
360102 -- Metals & Alloys-- Structure & Phase Studies
ALKALINE EARTH METALS
CHALCOGENIDES
COBALT COMPOUNDS
COBALT OXIDES
COHERENT SCATTERING
DATA
DATA ANALYSIS
DIFFRACTION
ELEMENTS
EXPERIMENTAL DATA
INFORMATION
MANGANESE
MEASURING INSTRUMENTS
MEASURING METHODS
METALS
NEUTRON DIFFRACTION
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
SCATTERING
STRONTIUM
STRUCTURAL CHEMICAL ANALYSIS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
X-RAY DIFFRACTION