Scaling of Jc- B curves in BSCCO/Ag tapes

Critical current density J_c of high- J_c, Ag-clad Bi ₂Sr ₂CaCu ₂O _8+x and (Bi,Pb) ₂Sr ₂Ca ₂Cu ₃O _10+y tapes has been studied in the temperature (T) range 4.5-92 K and magnetic field B ≤ 1 T. Both types of tapes exhibit clear scaling of J_c and the pinning force density F_p = J_cB with B for {T}/{T _c} > 0.4 . The scaling field B ^∗ ( F_p reaches its maximum for B = B ^∗) shows an exp(- {T}/{T ₀}) variation with T₀ ≈ 11 K for {T}/{T _c} < 0.8 . The implications of these results for the understanding of J_c in high- T_c superconductors and the practical applications of BSCCO/Ag tapes are briefly discussed.