Composite reaction texturing of superconducting ceramic composites

Textured composite Bi₂Sr₂Ca₁Cu₂O_8+a (2212) conductors have been fabricated by a novel method termed composite reaction texturing (CRT) that makes use of inert whiskers or fibers to align superconducting grains and control their morphology. The process has two stages, the initial alignment of fibre material in a precursor followed by a composite reaction stage to develop a textured microstructure. In this work, disk-shaped pellets with whisker alignment in the pellet plane were reacted to produce CRT material with a transport critical-current density in excess of 4×10³ A cm^-2 at 77 K (B=0). At 4.5 K, the critical-current density was ∼10⁵ A cm^-2 in zero field and 2.10⁴ A cm^-2 at 12 T. The method clearly has promise for the production by a wind-and-react technique of high critical-current conductors with large cross sections.