Phase stability and decomposition of superconductive YBa sub 2 Cu sub 4 O sub 8

Journal Article · Mon Jul 02 04:00:00 EDT 1990 · Applied Physics Letters; (USA)

DOI:https://doi.org/10.1063/1.104236· OSTI ID:6753814

Wada, T; Suzuki, N; Ichinose, A; Yaegashi, Y; Yamauchi, H; Tanaka, S ^[1]

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1. Superconductivity Research Laboratory, International Superconductivity Technology Center, 10-13 Shinonome 1-Chome, Koto-ku, Tokyo 135 (Japan)

The stability of the YBa{sub 2}Cu{sub 4}O{sub 8} phase has been studied with respect to oxygen partial pressure {ital P}(O{sub 2} ) and temperature by x-ray diffraction, thermogravimetry, and differential thermal analysis. The critical temperature {ital T}{sub {ital d}} for the decomposition of YBa{sub 2}Cu{sub 4}O{sub 8} phase was determined from thermal analyses. It was found that {ital T}{sub {ital d}} was strongly dependent on {ital P}(O{sub 2} ) and the following empirical relation was obtained: log({ital P}(O{sub 2})(atm)) = 12.41 {minus} (1.449 {times} 10{sup 4})/{ital T}{sub {ital d}}(K). It was found that, when heated, YBa{sub 2}Cu{sub 4}O{sub 8} first decomposed into YBa{sub 2} Cu{sub 3.5} O{sub 7.5{minus}{ital z}} plus CuO for 0.02 atm{lt}{ital P}(O{sub 2} ){lt}9 atm, while for {ital P}(O{sub 2}){le}0.02 atm, it decomposed into YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital z}} plus CuO without yielding YBa{sub 2}Cu{sub 3.5}O{sub 7.5{minus}{ital z}}.

• OSTI ID: 6753814
• Journal Information: Applied Physics Letters; (USA), Journal Name: Applied Physics Letters; (USA) Vol. 57:1; ISSN APPLA; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
COPPER COMPOUNDS
COPPER OXIDES
CRYSTAL-PHASE TRANSFORMATIONS
DECOMPOSITION
DIAGRAMS
HIGH-TC SUPERCONDUCTORS
OXIDES
OXYGEN COMPOUNDS
PHASE DIAGRAMS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
STABILITY
SUPERCONDUCTORS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
YTTRIUM COMPOUNDS
YTTRIUM OXIDES