MICROFILAMENTARY CONDUCTOR BASED ON BI(2212)

A series of ex-situ prepared microfilamentary conductors have been prepared to determine the optimum heat treatment sequence for the development of a strain tolerant microfilamentary conductor based on Bi2Sr2Ca1Cu2O8-delta. In this work, both monolithic tapes and the microfilamentary composites were prepared so that the difference between the two methods for the same heat treatment could be evaluated. The monolithic tapes are easy to fabricate and are used to provide a rough guide to the desired degree of melting and the optimum oxygen concentration needed for the highest critical current densities. One of the ex-situ microfilamentary composities showed a critical current density of 5000 A/cm2 at 4.2K while subjected to a strain exceeding 1%.