DIRECT PERITECTIC GROWTH OF C-AXIS TEXTURED YBA2CU3OX ON A FLEXIBLE METALLIC SUBSTRATE

Previous work in the development of YBa2Cu3Ox (YBCO) superconducting w ires and tapes has been focused on the deposition of YBCO on buffered metallic substrates. Although such an approach has proved successful i n terms of achieving grain texturing and high transport current densit y, critical issues involving continuous processing of long-length cond uctors and stabilization of the superconductor have not yet been entir ely settled. We have developed a novel process, the so-called direct p eritectic growth (DPG), in which textured YBCO thick films have been s uccessfully deposited directly onto a silver alloy substrate. No buffe r layer is employed in the film deposition process. The textured YBCO grains have been obtained through peritectic solidification over a wid e range of temperatures and times. The substrate materials have not de monstrated any observable reaction with the YBCO melt at the maximum p rocessing temperature near 1010 degrees C. The transport J(c) has reac hed a respectable value of 10(4) A/cm(2) at 77 K and zero magnetic fie ld. Based on the experimental results in this work, we show that the D PG method offers an effective alternative for the fabrication of long- length YBCO conductors. Also reported is a physical explanation of the texturing mechanism on the metal substrate.