La/sub 8-x/Sr/sub x/Cu/sub 8/O/sub 20/: an oxygen-deficient perovskite built of CuO/sub 6/, CuO/sub 5/, and CuO/sub 4/ polyhedra
Journal Article
·
· J. Solid State Chem.; (United States)
A new oxygen-deficient perovskite corresponding to the formulation La/sub 8-x/Sr/sub x/Cu/sub 8/O/sub 20-epsilon/ (1.28 less than or equal to x less than or equal to 1.92) has been isolated. The results of chemical analysis show that copper exhibits a mixed valence in this oxide. This perovskite crystallizes in a tetragonal cell with parameters related to the a/sub p/ parameter of the cubic perovskite by: a approx. = a/sub p/ 2 ..sqrt.. 2, c approx. = a/sub p/. The structure has been determined by neutron powder diffraction in the space group p4mbm. This study shows that the oxygen vacancies are ordered, forming rows parallel to (001). The (Cu/sub 8/O/sub 20/) framework is built of corner-sharing CuO/sub 6/ octahedra. CuO/sub 5/ pyramids, and CuO/sub 4/ square planar groups forming hexagonal tunnels in which are located the La/sup 3 +/ And Sr/sup 2 +/ ions. The slight oxygen substoichiometry with regard to the formulation A/sub 8/Cu/sub 8/O/sub 20/ is discussed in terms of a superstructure along the c axis (c approx. 2a/sub p/), which was observed in some crystals by electron diffraction.
- Research Organization:
- Universite de Caen (France)
- OSTI ID:
- 7007121
- Journal Information:
- J. Solid State Chem.; (United States), Journal Name: J. Solid State Chem.; (United States) Vol. 73:2; ISSN JSSCB
- Country of Publication:
- United States
- Language:
- English
Similar Records
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BaLa/sub 4/Cu/sub 5/O/sub 13 + delta/, an oxygen-deficient perovskite built up from corner-sharing CuO/sub 6/ octahedra and CuO/sub 5/ pyramids
Journal Article
·
Sun Oct 31 23:00:00 EST 1993
· Journal of Solid State Chemistry; (United States)
·
OSTI ID:7274279
Powder neutron diffraction study of the ordered oxygen-deficient perovskites (La,Sr){sub 8}Cu{sub 8-x}Fe{sub x}O{sub 20}
Journal Article
·
Tue Oct 31 23:00:00 EST 1995
· Chemistry of Materials
·
OSTI ID:415037
BaLa/sub 4/Cu/sub 5/O/sub 13 + delta/, an oxygen-deficient perovskite built up from corner-sharing CuO/sub 6/ octahedra and CuO/sub 5/ pyramids
Journal Article
·
Fri May 01 00:00:00 EDT 1987
· J. Solid State Chem.; (United States)
·
OSTI ID:6560959
Related Subjects
36 MATERIALS SCIENCE
360201 -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ALKALINE EARTH METAL COMPOUNDS
CATIONS
CHALCOGENIDES
CHARGED PARTICLES
CHEMICAL PREPARATION
COHERENT SCATTERING
COPPER COMPOUNDS
COPPER OXIDES
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DATA
DIFFRACTION
ELECTRON DIFFRACTION
EXPERIMENTAL DATA
INFORMATION
IONS
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
RARE EARTH COMPOUNDS
SCATTERING
SPACE GROUPS
STOICHIOMETRY
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
SYNTHESIS
TETRAGONAL LATTICES
TRANSITION ELEMENT COMPOUNDS
360201 -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ALKALINE EARTH METAL COMPOUNDS
CATIONS
CHALCOGENIDES
CHARGED PARTICLES
CHEMICAL PREPARATION
COHERENT SCATTERING
COPPER COMPOUNDS
COPPER OXIDES
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DATA
DIFFRACTION
ELECTRON DIFFRACTION
EXPERIMENTAL DATA
INFORMATION
IONS
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
RARE EARTH COMPOUNDS
SCATTERING
SPACE GROUPS
STOICHIOMETRY
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
SYNTHESIS
TETRAGONAL LATTICES
TRANSITION ELEMENT COMPOUNDS