Fabrication of Y123 coated conductors using metal organic decomposition process

Abstract

Recent trends in HTS research have been geared toward development of coated conductors. In these conductors, a flexible metallic substrate, typically a nickel alloy, is covered successively with one or more thin buffer layer such as YSZ, STO, MgO, etc., and a relatively thick film of Y123. To make the fabrication of such conductors scalable and cost effective, this paper demonstrates the application of metal organic decomposition techniques to deposit the buffer layers and the YBCO films. We present results obtained strontium titanate buffer layers. These buffer layers, processed on single crystal substrates using solution precursors and heat treated in a reducing atmosphere are highly textured and have a uniform smooth surface. YBCO films, 0.3–0.5μm thick, deposited on these buffered single crystals using the trifluoroacetate process shows good superconducting properties. YBCO films processed on strontium titanate buffered lanthanum aluminate substrates have transition temperatures of 90–91 K and critical current densities of the order of 10 5 A/cm 2 at 77K and self field. These processing techniques have been extended to textured nickel substrates. These results offer promise to the development of a scalable, solution based processing route to deposit buffer layers and YBCO films on flexible metallic textured tapes.