Epitaxial superconductors on rolling-assisted biaxially-textured substrates (RABiTS): A route towards high critical current density wire

Fabrication of epitaxial, high-J(c), biaxially aligned YBCO thick films on rolling-assisted biaxially-textured substrates (RABiTS) is summarized. The RABiTS technique utilizes standard thermomechanical processing to obtain long lengths of flexible, biaxially oriented substrates with smooth surfaces (rms similar to 50 nm). The strong biaxial texture of the metal (in-plane 6-7 degrees FWHM) is conferred to the superconductor by deposition of intermediate metal and/or oxide layers which serve both as a chemical as well as a structural buffer. Epitaxial YBCO films grown using laser ablation on RABiTS(TM) have critical current densities exceeding 10(6) A cm(-2) at 77 K in zero-field and have field dependences similar to epitaxial films on single crystal ceramic substrates. The texture of the base metal has been achieved in lengths over 1 m and scaleable techniques are being pursued to deposit epitaxial multilayers. Deposited conductors made using this technique offer a potential route for the fabrication of long lengths of high-J(c) wire capable of carrying high currents in high magnetic fields and at elevated temperatures. (C) 1998 Elsevier Science Ltd. All rights reserved.