Study on chemical diffusion of oxygen in Ba sub 2 YCu sub 3 O sub 7-. delta

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

DOI:https://doi.org/10.1016/0022-4596(89)90283-1· OSTI ID:7172016

Kishio, K; Suzuki, K; Hasegawa, T; Yamamoto, T; Kitazawa, K ^[1]; Fueki, K ^[2]

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1. Univ. of Tokyo (Japan)
2. Science Univ. of Tokyo (Japan)

Chemical diffusion in the high-T{sub c} oxide superconductor Ba{sub 2}YCu{sub 3}O{sub 7-{delta}} system was thermogravimetrically studied in a temperature range from 550 to 850{degree}C under an oxygen pressure of 1 to 10{sup {minus}2} atm, using highly densified polycrystalline specimens. Isothermal weight relaxation after stepwise changes of the oxygen pressure were measured and analyzed in terms of oxygen diffusion-controlled kinetics. The chemical diffusion coefficient was found to be strongly sensitive to the oxygen composition. Its absolute value sharply increased with decreasing oxygen deficiency, {delta}, although it did not change appreciably at the structural transition between orthorhombic and tetragonal phases. Such a compositional dependence of the chemical diffusion is not expected from a simple vacancy diffusion mechanism. It is interpreted in terms of composition-sensitive activation energy for the two-dimensional motion of oxygen within the unique crystal structure of this oxide system.

• OSTI ID: 7172016
• Journal Information: Journal of Solid State Chemistry; (USA), Journal Name: Journal of Solid State Chemistry; (USA) Vol. 82:2; ISSN 0022-4596; ISSN JSSCB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360000* -- Materials
360203 -- Ceramics
Cermets
& Refractories-- Mechanical Properties
360603 -- Materials-- Properties
ALKALINE EARTH METALS
BARIUM
CHALCOGENIDES
CHEMICAL ANALYSIS
COMPOSITE MATERIALS
COPPER COMPOUNDS
COPPER OXIDES
DATA
DATA ANALYSIS
DIFFUSION
ELEMENTS
EXPERIMENTAL DATA
HIGH TEMPERATURE
INFORMATION
LOW PRESSURE
MATERIALS
MEASURING INSTRUMENTS
MEASURING METHODS
METALS
NONMETALS
NUMERICAL DATA
OXIDES
OXYGEN
OXYGEN COMPOUNDS
SUPERCONDUCTING COMPOSITES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
YTTRIUM