Oxidation induced decomposition of YBa sub 2 Cu sub 3 O sub 7 minus x

Journal Article · Mon Jul 15 00:00:00 EDT 1991 · Journal of Applied Physics; (USA)

DOI:https://doi.org/10.1063/1.349597· OSTI ID:5732096

Williams, R K; Alexander, K B; Brynestad, J; Henson, T J; Kroeger, D M; Lindemer, T B; Marsh, G C; Scarbrough, J O; Specht, E D ^[1]

---

1. Oak Ridge National Laboratory, P. O. Box 2008, Oak Ridge, Tennessee 37831 (US)

At low oxygen potentials, YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} decomposes by chemical reactions involving reduction. The results of this study show that the compound also decomposes at higher oxygen potentials. The initial decomposition products were found to be Y{sub 2}BaCuO{sub 5} and a Ba-Cu oxide phase. The Ba-Cu phase was found to be a peroxide-type and the decomposition can be described by a chemical reaction involving oxidation: 4(YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}}) + (1/2 {minus} 3/2{delta} + 2{ital x})O{sub 2}{r reversible}2Y{sub 2}BaCuO{sub 5} + 3Ba{sub 2}Cu{sub 3}O{sub 6{minus}{delta}} + CuO. At 800 {degree}C the equilibrium pressure for this reaction is slightly {lt}1 bar, and the enthalpy change is {similar to}80-kJ/mol Y123. This result is not consistent with the conclusions drawn from some other studies of the stability of the superconducting Y-Ba-Cu-O compounds, and the differences are discussed.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5732096
• Journal Information: Journal of Applied Physics; (USA), Vol. 70:2; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
DECOMPOSITION
COPPER OXIDES
HIGH-TC SUPERCONDUCTORS
YTTRIUM OXIDES
CHEMICAL REACTION KINETICS
CRITICAL CURRENT
ORNL
OXIDATION
QUATERNARY COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
AMINES
AMMONIUM COMPOUNDS
BARIUM COMPOUNDS
CHALCOGENIDES
CHEMICAL REACTIONS
COPPER COMPOUNDS
CURRENTS
ELECTRIC CURRENTS
KINETICS
NATIONAL ORGANIZATIONS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
REACTION KINETICS
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
US AEC
US DOE
US ERDA
US ORGANIZATIONS
YTTRIUM COMPOUNDS
360202* - Ceramics
Cermets
& Refractories- Structure & Phase Studies
360205 - Ceramics
Cermets
& Refractories- Corrosion & Erosion