Liquidus relations in Y--Ba--Cu oxides
Journal Article
·
· J. Mat. Res.; (United States)
The liquidus relations in the system YO/sub 1.5/--BaO--CuO/sub x/ in air in the compositional region near the superconducting oxide YBa/sub 2/Cu/sub 3/O/sub x/ were studied by differential thermal analysis, x-ray diffraction, electron microprobe analysis, and visual observation. The temperatures of 11 invariant points and the corresponding reactions were determined. YBa/sub 2/Cu/sub 3/O/sub x/ was found to melt incongruently at 1015 /sup 0/C to Y/sub 2/BaCuO/sub 5/, which in turn melts incongruently to Y/sub 2/O/sub 3/ at 1270 /sup 0/C. These reactions mean that preparing the superconducting phase by melting and rapid cooling will result in the presence of these two phases as well. The peritectic reaction YBa/sub 2/Cu/sub 3/O/sub x/+CuO..-->..Y/sub 2/BaCuO/sub 5/+liquid at 940 /sup 0/C accounts for the observation of partial melting, improved synthesis purity, and grain growth at temperatures of 950 /sup 0/C. The determination of these invariant temperatures and reactions provide insight into optimal processing conditions.
- Research Organization:
- Electronic Ceramics Division 1842 and Ceramics Development Division 1845, Sandia National Laboratories, Albuquerque, New Mexico 87185
- OSTI ID:
- 6727236
- Journal Information:
- J. Mat. Res.; (United States), Journal Name: J. Mat. Res.; (United States) Vol. 3:6; ISSN JMREE
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMICAL PREPARATION
COHERENT SCATTERING
COPPER COMPOUNDS
COPPER OXIDES
CRYSTAL-PHASE TRANSFORMATIONS
DIAGRAMS
DIFFRACTION
ELECTRON MICROPROBE ANALYSIS
HIGH TEMPERATURE
MELTING
MICROANALYSIS
OXIDES
OXYGEN COMPOUNDS
PHASE DIAGRAMS
PHASE TRANSFORMATIONS
SCATTERING
STRUCTURAL CHEMICAL ANALYSIS
SYNTHESIS
THERMAL ANALYSIS
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION
YTTRIUM COMPOUNDS
YTTRIUM OXIDES
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMICAL PREPARATION
COHERENT SCATTERING
COPPER COMPOUNDS
COPPER OXIDES
CRYSTAL-PHASE TRANSFORMATIONS
DIAGRAMS
DIFFRACTION
ELECTRON MICROPROBE ANALYSIS
HIGH TEMPERATURE
MELTING
MICROANALYSIS
OXIDES
OXYGEN COMPOUNDS
PHASE DIAGRAMS
PHASE TRANSFORMATIONS
SCATTERING
STRUCTURAL CHEMICAL ANALYSIS
SYNTHESIS
THERMAL ANALYSIS
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION
YTTRIUM COMPOUNDS
YTTRIUM OXIDES