Oxygen ordering and the orthorhombic-to-tetragonal phase transition in YBa/sub 2/Cu/sub 3/O/sub 7-//sub x/

Journal Article · Tue Sep 01 00:00:00 EDT 1987 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.36.3608· OSTI ID:6231376

Jorgensen, J D; Beno, M A; Hinks, D G; Soderholm, L; Volin, K J; Hitterman, R L; Grace, J D; Schuller, I K; Segre, C U; Zhang, K

In situ neutron powder diffraction measurements show that the orthorhombic-to-tetragonal phase transition in YBa/sub 2/Cu/sub 3/O/sub 7-//sub x/ which occurs near 700 /sup 0/C in a pure oxygen atmosphere, is an order-disorder transition in which the disordering of oxygen atoms into a normally vacant site destroys the one-dimensional Cu-O chains present in the room-temperature orthorhombic structure. For both structures, the oxygen stoichiometry decreases monotonically with increasing temperature. The transition temperature depends on the oxygen partial pressure and occurs when the stoichiometry is near YBa/sub 2/Cu/sub 3/O/sub 6.5/. The tetragonal structure has a partially occupied, nearly octahedral Cu-O arrangement, in contrast to the orthorhombic structure which has one-dimensional Cu-O chains. The observed depression of the superconducting transition temperature in tetragonal YBa/sub 2/Cu/sub 3/O/sub 7-//sub x/, which has been quenched from high temperature, could result either from the disordering of oxygen atoms which destroys the one-dimensional chains or from the absence of Cu/sup 3+/ ions.

• Research Organization: Argonne National Laboratory, Argonne, Illinois 60439
• OSTI ID: 6231376
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Vol. 36:7
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BARIUM OXIDES
CRYSTAL-PHASE TRANSFORMATIONS
ORDER-DISORDER TRANSFORMATIONS
COPPER OXIDES
YTTRIUM OXIDES
HIGH TEMPERATURE
NEUTRON DIFFRACTION
POWDERS
SUPERCONDUCTIVITY
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
CHALCOGENIDES
COHERENT SCATTERING
COPPER COMPOUNDS
DIFFRACTION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
SCATTERING
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
360202* - Ceramics
Cermets
& Refractories- Structure & Phase Studies
656100 - Condensed Matter Physics- Superconductivity