Tracer diffusion of Ba and Y in YBa sub 2 Cu sub 3 O sub x

Journal Article · Tue Sep 01 04:00:00 EDT 1992 · Journal of Materials Research; (United States)

DOI:https://doi.org/10.1557/JMR.1992.2308· OSTI ID:7229001

Chen, N; Rothman, S J; Routbort, J L ^[1]; Goretta, K C ^[2]

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1. Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
2. Materials and Components Technology Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

Tracer self-diffusion of Ba and Y and the diffusion of Dy, Ho, and Gd, which substitute for Y, have been measured in polycrystalline YBa{sub 2}Cu{sub 3}O{sub {ital x}} over temperature and oxygen partial pressure ranges of 850 to 980 {degree}C and 10{sup 3} to 10{sup 5} Pa, respectively. The diffusion of Ba is slower than that of oxygen or copper, with a high activation energy of about 890{plus minus}80 kJ/mole. Large anisotropy has also been observed, with diffusion along the {ital c}-axis being more than three orders of magnitude slower than diffusion in randomly oriented polycrystals. Diffusion coefficients of Ba were, within experimental uncertainty, independent of oxygen partial pressure over the range measured. The diffusion coefficients of the Y-site species were nearly identical and an activation energy of about 1.0 MJ/mole was estimated, in agreement with that for high-temperature deformation. Attempts to speed up the kinetics through creation of point defects on the Y site by doping proved to be unsuccessful. These results are compared to cation diffusion in cubic perovskites and simple oxides.

• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 7229001
• Journal Information: Journal of Materials Research; (United States), Journal Name: Journal of Materials Research; (United States) Vol. 7:9; ISSN JMREE; ISSN 0884-2914
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ACTIVATION ENERGY
ALKALINE EARTH METAL COMPOUNDS
ALKALINE EARTH METALS
ANISOTROPY
ATOM TRANSPORT
BARIUM
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
CRYSTALS
DIFFUSION
ELEMENTS
ENERGY
HIGH-TC SUPERCONDUCTORS
LOW PRESSURE
METALS
NEUTRAL-PARTICLE TRANSPORT
OXIDES
OXYGEN COMPOUNDS
POLYCRYSTALS
RADIATION TRANSPORT
SELF-DIFFUSION
SUPERCONDUCTORS
TEMPERATURE RANGE
TEMPERATURE RANGE 1000-4000 K
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
YTTRIUM
YTTRIUM COMPOUNDS
YTTRIUM OXIDES