Improved YBCO coated conductors using alternate buffer architectures

The Rolling-Assisted Biaxially Textured Substrates (RABiTS) process has been identified as one of the leading candidates for the fabrication of high performance YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// (YBCO) coated conductors. The RABiTS process uses standard thermomechanical processing to obtain long lengths of flexible, biaxially oriented substrates with smooth surfaces. The strong biaxial texture of the metal is then transferred to the superconductor by the deposition of intermediate oxide buffers that serve both as a chemical and structural buffer. The typical three-layer RABiTS architecture consists of an e-beam Y/sub 2/O/sub 3/ seed, sputtered YSZ barrier and a sputtered CeO/sub 2/ cap layer. Chemical solution deposition of buffer layers offers potential cost advantage relative to physical vapor deposition (PVD) processes. Our main goal of this study is to develop simplified buffer architectures and demonstrate high J/sub c/ Metal-Organic Deposition (MOD)-YBCO films on all-MOD buffers. La/sub 2/Zr/sub 2/O/sub 7/ (LZO)/CeO/sub 2/ buffers have been identified as potential candidates for this study. MOD-YBCO films with a critical current, I/sub c/ of 212 A/cm have been achieved on MOD-LZO seeds with sputtered YSZ and CeO/sub 2/ cap layers. In addition, MOD-YBCO films with a critical current, I/sub c/ of 140 A/cm have been achieved on all MOD buffers of LZO/CeO/sub 2/ for the first time. This offers a potential toward fabrication of lower cost YBCO coated conductors.