CO-REACTION OF TEXTURED SUPERCONDUCTING, CONDUCTING AND INSULATING MULTILAYER COMPOSITES

Many applications of superconductors are limited by low values of the engineering critical current density (J(ce)). Significant improvements are possible through the merger of green tape and composite reaction texturing technologies, Tape casting and elastomer processing techniqu es have produced insulating (MgO and Al2O3), conducting (Ag) and super conducting (Bi-2212 + MgO-fibre) tapes with uniform thickness ranging from 0.1-2mm. Green tapes of the desired thickness can be laminated in to multilayer structures and co-reacted; the superconducting layer occ upying over 50% of the cross section allows the engineering of an arte fact for optimal I-c and maximum J(ce). The texture observed in the Bi -2212 layer is induced by specifically aligned MgO-fibres. As a necess ary step in developing this technology results are presented on (1) ad ditions of 0-10 %wt Ag to Bi-2212 in order to modify its partial melt behaviour, (2) control of the shrinkage and densification of individua l layers which is critical to uniformity and (3) chemical buffering of the Bi-2212 layer from reactive insulating layers of doped MgO and Al 2O3 during co-reaction.