Angular, Temperature, and Strain Dependencies of the Critical Current of DI-BSCCO Tapes in High Magnetic Fields

摘要

High critical current density $(J_{c})$ DI-BSCCO Bi-2223 superconducting tape has been developed by Sumitomo Electric Industries (SEI) using the Controlled Over-Pressure (CT-OP) technique to improve the texturing and densification. Further enhancement of the mechanical properties has been obtained using lamination. We have investigated the effect of magnetic field and field orientation on $J_{c}$ for a series of test DI-BSCCO tapes at 77 K and 4.2 K under tensile and compressive strains. These critical current data are strongly influenced by the anisotropy of Bi-2223, the texturing of the tape and its architecture. The magnetic field and angular dependence of $J_{c}$ at 77 K can be described using a simple anisotropic exponential magnetic field model which includes the effects of the two-dimensionality and grain misalignment in these composites. The variation in the normalized $J_{rm c}$ with respect to the strain is linear over the reversible range of strain where the gradient of the strain dependence is independent of temperature and field. The reversibility of $J_{rm c}$ is extended further into the compressive regime after $J_{rm c}$ degradation by compression.