Abstract
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Nearly 95 vol% of the 110 K superconducting phase was formed by lead doping in a Bi-Sr-Ca-Cu-O system. The processed 110 K superconducting powders were used to produce long silver-sheathed tapes with a highly textured microstructure by rolling and prolonged sintering. The transport critical current density was measured at 4.0 K to be 0.7��105 A/cm2 (the corresponding critical current is 74 A) at zero field and 1.6��10 4 A/cm2 at 12 T for H���ab. At 76 K, the critical current density reached a value of ���1��104 A/cm2 at zero field for H���ab and gradually decreased to 419 A/cm2 at 1 T. Excellent grain alignment in the a-b plane led to greatly improved critical current densities under a magnetic field. The relationship between the transport properties and the microstructure of the tapes is discussed.