PREPARATION AND CRITICAL-CURRENT DENSITY OF BI-BASED SUPERCONDUCTING WHISKER COMPOSITES

Bi2Sr2CaCu2Ox (Bi-2212) superconducting whisker composites densified a nd textured by hot pressing have been prepared. The composites consist of Bi-2212 whiskers and Bi-2212 powder and include the whiskers by 5. 0 and 10 wt%. The ab-plane of the whiskers and the grains is aligned p arallel with the pressed plane of the composites. Although zero resist ance temperature (T-c,T-zero) is not so different between the composit es and the sample without the whiskers, critical current density (J(c) ) for the 10 wt% composite is 14 times larger than that for the sample without the whiskers at 77 K under zero magnetic field. The increase in J(c) is caused by an improvement of the grain growth and alignment around the whiskers. (C) 1996 Elsevier Science Limited and Techna S.r. l.