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 04:00:00 EDT 1987 · J. Solid State Chem.; (United States)

DOI:https://doi.org/10.1016/0022-4596(87)90297-0· OSTI ID:6560959

Michel, C; Rakho Er, L; Hervieu, M; Pannetier, J; Raveau, B

The structure of an oxygen-deficient perovskite BaLa/sub 4/Cu/sub 5/O/sub 13 + delta/ has been determined by neutron powder diffraction and high-resolution electron microscopy. It has been resolved in the space group P4/m(a approx. a/sub p/ ..sqrt.. 5, c approx. a/sub p). The framework (Cu/sub 5/O/sub 13/) is built up from corner-sharing CuO/sub 5/ pyramids and CuO/sub 6/ octahedra forming hexagonal tunnels and perovskite cages where the La/sup 3 +/ and Ba/sup 2 +/ ions are located in an ordered manner. The barium ions are located in the perovskite tunnels whereas the lanthanum ions are located in the hexagonal tunnels. A great number of crystals exhibit a single oxygen-deficient perovskite which can be considered as having the stoichiometry BaLa/sub 4/Cu/sub 5/O/sub 13/; the excess of oxygen, delta, corresponds to the formation in other crystals of superstructures (approx. a/sub p/ ..sqrt.. 10 x ..sqrt.. a/sub p/ ..sqrt.. 10 x a/sub p) and of microdomains which are interpreted as the result of a distortion of the (Cu/sub 5/O/sub 13/) matrix induced by the introduction of oxygen in half of the hexagonal tunnels.

• Research Organization: ISMRa-Universite, Caen, France
• OSTI ID: 6560959
• Journal Information: J. Solid State Chem.; (United States), Journal Name: J. Solid State Chem.; (United States) Vol. 68:1; ISSN JSSCB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COHERENT SCATTERING
COPPER COMPOUNDS
COPPER OXIDES
CRYSTAL STRUCTURE
DATA
DIFFRACTION
ELECTRON MICROSCOPY
EXPERIMENTAL DATA
INFORMATION
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
MICROSCOPY
NEUTRON DIFFRACTION
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
POWDERS
RARE EARTH COMPOUNDS
SCATTERING
SPACE GROUPS
STOICHIOMETRY
TRANSITION ELEMENT COMPOUNDS