CRITICAL-CURRENT DENSITY DISTRIBUTION IN THE SUPERCONDUCTING OXIDE LAYER OF PRE-ANNEALING AND INTERMEDIATE-ROLLING PROCESSED BI2SR2CACU2OX AG COMPOSITE TAPES/

The critical current density (J(c)) distribution in the oxide layer of PAIR (pre-annealing and intermediate rolling) processed Bi2Sr2CaCu2Ox (Bi-2212)/Ag composite tapes is studied in order to give a clear expl anation for the large J(c) enhancement by the PAIR process. J(c) of th e oxide layer within 2 mu m from the Bi-2212/Ag interface exceeds 3.8 x 10(5) A cm(-2) at 4.2 K and 10 T. No significant increase of J(c)(lo cal) is confirmed in the Bi-2212 layer at less than 2 mu m from the in terface. However, J(c)(local) increases by performing the PAIR process in the middle part of the Bi-2212 layer 2-15 mu m from the interface. J(c)(local) is 2.4 x 10(5) A Cm-2 and 1.0 x 10(5) A Cm-2 at distances of 5 mu m and IO mu m from the interface respectively. The results in dicate that the large J(c) enhancement by the PAIR process can be attr ibuted to higher J(c)(local) in this middle part. J(c) improvement in the part near the free surface is also achieved by the PAIR process an d contributes to high J(c).