The Influence of Pre-Existing Defects on the Bending Strain Behavior of Bi2Sr2Ca1Cu2Ox and (Bi,Pb)2Sr2Ca2Cu3Ox Ag-Sheathed Tapes
The effect of pre-existing defects on the bend strain behavior in Bi2Sr2Ca,Cu2OX (Bi-2212) and (Bi,Pb)2Sr2Ca2Cu3OX (Bi-2223) Ag-sheathed tapes was studied. For Bi-2212 at 4.2 K, we found that the transport critical current (Ic) declined by only 1% at bending strains less than 0.15%. However, the magnetization critical current density was sensitive to small bending strains, as evidenced by a strain of ~ 0.08%, which reduced the magnetization by 25%. For pressed Bi-2223 tapes at 77 K, essentially no reduction in was observed for strains less than 0.1%. At strains greater than 0.2%, lc dropped to only 10% of its original value at a strain of ~0.4%. The magnetization of pressed Bi-2223 at 77 K responded similarly to that of Bi-2212 tapes. Using magneto-optical imaging, we observed that the strain tolerance of Bi-2212 and Bi-2223 is strongly dependent on the pre-existing defects found in the cores of the tapes.
KeywordsTest Section Critical Current Indicator Film Advance Research Project Agency Silver Sheath
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- 1.J. W. Ekin, D. K. Finnemore, Qiang Li, J. Tenbrink, W. Carter, Appl. Phys. Lett. 61: 858 (1992).Google Scholar
- 10.A. Polyanskii, A. Pashitski, A. Gurevich, J. A. Parrell, M. Polak, D. C. Larbalestier, S. R. Foltyn, and P. N. Arendt, ISS’96, Sapporo, Japan (1996).Google Scholar