Characterization of YBCO Superconductor Sintered in CO₂-Containing Atmosphere

Conference · Mon Nov 12 04:00:00 EST 1990

OSTI ID:5941267

Balachandran, U. ^[1]; Poeppel, R. B. ^[1]; Dorris, S. E. ^[1]; Zhang, C. Z. ^[1]; Xu, D. ^[1]; Merkle, K. ^[1]; Gao, Y. ^[1]; Li, Y. ^[1]; Picciolo, J. J. ^[1]; Dusek, J. T. ^[1]; Selvaduray, G. ^[2]

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1. Argonne National Laboratory (ANL), Argonne, IL (United States)
2. San Jose State Univ., CA (United States)

The importance of closely controlling the furnace atmosphere during processing of YBa₂Cu₃O_7-x [YBCO) was examined. The stability of YBCO during sintering was studied as a function of CO₂ partial pressure in CO₂ containing O₂ gas mixtures. The zero-field critical current density, J_c. decreased with increasing CO₂ partial pressure, and ultimately reached zero, even though Meissner effect measurements showed that the bulk of the samples with zero transport J_c remained superconducting. Transmission electron microscopy of materials sintered in O₂ atmospheres containing various levels of CO₂ clearly showed the extent of grain boundary degradation. Binder removal from plastically processed superconductors, such as wires and coils give off harmful gases such as CO₂, and H₂O. The wires and coils can be fired successfully if the furnace atmosphere is carefully controlled. It was found that the use of reduced total pressure during binder burn-out and sintering prevents the decomposition of YBCO.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division (MSE); USDOE Office of Energy Efficiency and Renewable Energy (EERE); National Science Foundation (NSF)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 5941267
• Report Number(s): ANL/CP--70575; CONF-901125--14; ON: DE91010595; CNN: DMR8809854
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201 -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
CRITICAL CURRENT
CRYSTAL STRUCTURE
CURRENT DENSITY
CURRENTS
ELECTRIC CURRENTS
FABRICATION
HIGH-TC SUPERCONDUCTORS
MICROSTRUCTURE
OXIDES
OXYGEN COMPOUNDS
PARTIAL PRESSURE
SINTERING
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES