Effect of silver solubility on microstructure and superconducting properties of YBa sub 2 Cu sub 3 minus x Ag sub x O sub 7 minus. delta. superconductors

Journal Article · Sun Mar 01 04:00:00 EST 1992 · Journal of Applied Physics; (United States)

DOI:https://doi.org/10.1063/1.351088· OSTI ID:5042831

Joo, J; Singh, J P; Poeppel, R B ^[1]; Gangopadhyay, A K; Mason, T O ^[2]

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1. Materials and Components Technology Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
2. Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States)

The effect of silver (Ag) solubility on microstructure and superconducting properties of YBa{sub 2}Cu{sub 3{minus}{ital x}}Ag{sub {ital x}}O{sub 7{minus}{delta}} (0{le}{ital x}{le}0.5) superconductors has been evaluated. The solubility limit of Ag for copper sites in YBCO at ambient conditions (room temperature, atmospheric pressure) was evaluated to be {ital x}{congruent}0.06. Analysis revealed the Ag content ({ital x}) of YBCO grains to be lower than the nominal Ag content ({ital x}{sub {ital n}}) used for fabrication, probably due to processing-related problems. Part of the Ag used for fabrication segregates on the YBCO grain boundaries. The segregated Ag particles are believed to pin YBCO grains, resulting in fine-grain microstructures. For low nominal Ag content, {ital x}{sub {ital n}}{lt}0.2, critical current density ({ital J}{sub {ital c}}) increased from 98 to 160 A/cm{sup 2} as a function of increasing Ag content. These improvements are believed to be due to the increased oxygen content and associated microstructural changes in the YBCO. For higher nominal Ag content, {ital x}{sub {ital n}}{gt}0.2, however, {ital J}{sub {ital c}} decreased rapidly with the increasing Ag content due to the precipitation of nonsuperconducting phases.

• OSTI ID: 5042831
• Journal Information: Journal of Applied Physics; (United States), Journal Name: Journal of Applied Physics; (United States) Vol. 71:5; ISSN 0021-8979; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360207* -- Ceramics
Cermets
& Refractories-- Superconducting Properties-- (1992-)
ALKALINE EARTH METAL COMPOUNDS
ALLOYS
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
CRITICAL CURRENT
CRYSTAL STRUCTURE
CURRENTS
ELECTRIC CURRENTS
HIGH-TC SUPERCONDUCTORS
MICROSTRUCTURE
OXIDES
OXYGEN COMPOUNDS
SILVER ADDITIONS
SILVER ALLOYS
SOLUBILITY
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES