All MOD buffer/YBCO approach to coated conductors

RABiTS based metal-organic deposition (MOD) buffer/YBa₂Cu₃O_7-δ (YBCO) approach has been considered as one of the potential, low-cost approaches to fabricate high performance second generation coated conductors. The most commonly used RABiTS architectures consisting of a starting template of biaxially textured Ni-W (5 at.%) substrate with a seed layer of Y₂O₃, a barrier layer of YSZ, and a CeO₂ cap. In this three layer architecture, all the buffers are deposited using physical vapor deposition (PVD) techniques. Using these PVD deposited templates, 0.8-μm thick MOD-YBCO films with an I_c (critical current) of 250 A/cm have been achieved routinely in short lengths. We have developed a low-cost, non-vacuum, MOD process to grow epitaxial buffer layers on textured Ni-5W substrates. The main challenge in this effort is to match the performance of MOD templates to that of PVD templates. We have recently shown that the properties of MOD-La₂Zr₂O₇ (LZO) layers can be improved by inserting a thin Y₂O₃ seed layer. Using MOD-CeO₂ cap layers, we have demonstrated the growth of high performance MOD-YBCO films with an I_c of 200 A/cm-width on MOD-La₂Zr₂O₇/Y₂O₃ /Ni-5W substrates. This approach could potentially decrease the overall cost of the coated conductor fabrication.