Effect of axial strain on the critical current of Ag-sheathed Bi-based superconductors in magnetic fields up to 25 T

Journal Article · Mon Aug 17 00:00:00 EDT 1992 · Applied Physics Letters; (United States)

DOI:https://doi.org/10.1063/1.107768· OSTI ID:7285535

Ekin, J W ^[1]; Finnemore, D K; Li, Q ^[2]; Tenbrink, J ^[3]; Carter, W ^[4]

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1. Electromagnetic Technology Division, National Institute of Standards and Technology, Boulder, Colorado 80303 (United States)
2. Department of Physics, Iowa State University, Ames, Iowa 50011 (United States)
3. Vacuumschmelze, GmbH, Hanau (Germany)
4. American Superconductor Corporation, Watertown, Massachusetts 02172 (United States)

The irreversible strain limit {epsilon}{sub irrev} for the onset of permanent axial strain damage to Ag-sheathed Bi{sub 2}Sr{sub 2}Ca{sub 1}Cu{sub 2}O{sub 8+{ital x}} and Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10+{ital x}} superconductors has been measured to be in the range of 0.2%--0.35%. This strain damage onset is about an order of magnitude higher than for {ital bulk} {ital sintered} Y-, Bi-, or Tl-based superconductors and is approaching practical values for magnet design. The measurements show that the value of {epsilon}{sub irrev} is not dependent on magnetic field, nor does the critical current depend on strain below {epsilon}{sub irrev} at least up to 25 T at 4.2 K. Both of these factors indicate that the observed strain effect in Ag-sheathed Bi-based superconductors is not intrinsic to the superconductor material. Rather, the effect is extrinsic and arises from superconductor fracture. Thus, the damage onset is amenable to further enhancement. Indeed, the data suggest that subdividing the superconductor into fine filaments or adding Ag to the superconductor powder prior to processing significantly enhances the damage threshold {epsilon}{sub irrev} to above 0.6%.

• OSTI ID: 7285535
• Journal Information: Applied Physics Letters; (United States), Vol. 61:7; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
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MECHANICAL PROPERTIES
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COPPER OXIDES
HIGH-TC SUPERCONDUCTORS
STRONTIUM OXIDES
SUPERCONDUCTING WIRES
CRITICAL CURRENT
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MAGNETIC FIELDS
MATERIALS TESTING
MIXED STATE
STRAINS
ALKALINE EARTH METAL COMPOUNDS
BISMUTH COMPOUNDS
CALCIUM COMPOUNDS
CHALCOGENIDES
COPPER COMPOUNDS
CURRENTS
ELECTRIC CURRENTS
FAILURES
OXIDES
OXYGEN COMPOUNDS
STRONTIUM COMPOUNDS
SUPERCONDUCTORS
TESTING
TRANSITION ELEMENT COMPOUNDS
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