Addition of nanometer SiC in the silver-sheathed Bi2223 superconducting tapes

Nanometer SiC particles were added to (Bi,Pb)(2)Sr2Ca2Cu3Ox (Bi2223) precur sor powders and the powders were transformed into silver-sheathed supercond ucting tapes by the standard powder-in-tube (PIT) technique. The influence of SiC on the melting temperature, high-ir, (Bi2223) phase formation, micro structure and transport property of the tapes was studied by means of DTA, XRD, SEM/EDX, electrical and magnetic measurements. The results showed that SIC addition lowered the melting temperature of the superconductor powders and consequently, decreased the optimum sintering temperature of the tapes . However, the addition did not affect the Bi2223 phase formation and criti cal temperature (T-c) of the tapes up to 1.00 wt.% of SiC. Most importantly , the addition of a small amount of SiC (0.15 wt.%) improved the critical c urrent (I-c) and I-c behavior in magnetic field as a result of the enhancem ent in density, grain alignment, grain connectivity and flux pinning of the tapes. (C) 1999 Published by Elsevier Science B.V. All rights reserved.