Abstract
The metal organic deposition (MOD) of buffer layers on RABiTS substrates is considered a potential, low-cost approach to manufacturing high performance Second Generation (2G) high temperature superconducting (HTS) wires. The typical architecture used by American Superconductor in their 2G HTS wire consists of a Ni-W (5 at.%) substrate with a reactlvely sputtered Y2O3 seed layer, YSZ barrier layer and a CeO2 cap layer. This architecture supports critical currents of over 300 A/cm-width (77 K, self-field) with 0.8 μm YBCO films deposited by the TFA-MOD process. The main challenge in the development of the MOD buffers is to match or exceed the performance of the standard vacuum deposited buffer architecture. We have recently shown that the texture and properties of MOD - La2Zr2O7 (LZO) barrier layers can be improved by inserting a thin sputtered Y2O 3 seed layer and prepared MOD deposited LZO layers followed by MOD or RF sputtered CeO2 cap layers that support MOD-YBCO films with I c's of 200 and 255 A/cm-width, respectively. Detailed X-ray and microstructural characterizations indicated that MOD -CeO2 cap reacted completely with MOD YBCO to form BaCeO3. However, sputtered CeO3 cap/MOD YBCO interface remains clean. By further optimizing the coating conditions and reducing the heat-treatment temperatures, we have demonstrated an Ic of 336 A/cm with improved LZO layers and sputtered CeO2 cap and exceeded the performance of that of standard vacuum deposited buffers.
Original language | English |
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Pages (from-to) | 3332-3335 |
Number of pages | 4 |
Journal | IEEE Transactions on Applied Superconductivity |
Volume | 17 |
Issue number | 2 |
DOIs | |
State | Published - Jun 2007 |
Funding
Manuscript received August 29, 2006. This work was supported in part by the US Department of Energy, Office of Electricity Delivery and Energy Reliability (OE), and Office of Science, Division of Materials Sciences. This research was performed at the Oak Ridge National Laboratory, managed by UT-Battelle, LLC for the USDOE Contract DE-AC05-00OR22725.
Keywords
- Chemical solution deposition
- Electron microscopy
- High temperature superconductors
- Transport property measurements
- X-ray measurements