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 YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// 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 YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// formation similar to those used in the growth of epitaxial thin films. The YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// phase was observed to grow near the Cu/sup I//Cu/sup II/ boundary. The growth step was followed by a low temperature anneal in one atm of oxygen. J/sub c/ and T/sub c/ values were found to depend strongly on processing conditions. With optimum processing, a T/sub c/ of 90 K and a J/sub c/ of 20kA/cm/sup 2/ at 65 K, were measured. XRD patterns of chemically etched surfaces of the processed tapes gave some evidence for epitaxial alignment of the YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// with the pre-textured silver matrix.