High performance superconducting Y-Ba-Cu-O tapes produced by oxidation of metallic precursors

A metallic precursor fabrication route has been developed for the production of multifilamentary tapes of textured YBa₂Cu₃ O_7-δ in a silver matrix. The number of filaments in prototype tapes ranged from 10 to 1024 with filament thickness from 1 to 40 microns. Following low temperature oxidation of the metallic precursor, we explored conditions for YBa₂Cu₃O_7-δ formation similar to those used in the growth of epitaxial thin films. The YBa₂Cu ₃O_7-δ phase was observed to grow near the Cu ^I/Cu^II boundary. The growth step was followed by a low temperature anneal in one atm of oxygen. J_c and T_c values were found to depend strongly on processing conditions. With optimum processing, a T_c of 90 K and a J_c of 20kA/cm² at 65 K, were measured. XRD patterns of chemically etched surfaces of the processed tapes gave some evidence for epitaxial alignment of the YBa₂Cu₃O_7-δ with the pre-textured silver matrix