Fabrication of Ag-Sheathed Bi-2223 Tapes Using Powders Produced by Aerosol Spray Pyrolysis

摘要

Bi-2223 tapes were manufactured from a fine "two-powder" product produced by using an aerosol spray pyrolysis technique. Critical current density of 22000 A/ cm~2 at 77K and 0 T was achieved. Nondestructive transmission x-ray diffraction study indicated good alignment of the superconducting grains. The texturing process of the superconducting phase was found to be nearly complete after the first 24 h of heat treatment for the samples studied. Pressing was found to play little role in the texturing process. The texturing can be enhanced by Ag-doping. J_c, however, was not found to be improved significantly, presumably due to the reduced effective cross-sectional area. A new phase, Bi-4435, was identified which may play a significant role in the formation of 2223.