Abstract
Two different types of defect structures have been identified to be responsible for the enhanced pinning in Metal Organic Deposited YBCO films. Rare earth additions result in the formation of nanodots in the YBCO matrix, which form uncorrected pinning centers, increasing pinning in all magnetic field orientations. 124-type intergrowths, which form as laminar structures parallel to the ab-plane, are responsible for the large current enhancement when the magnetic field is oriented in the ab-plane. TEM studies showed that the intergrowths emanate from cuprous containing secondary phase particles, whose density is partially controlled by the rare earth doping level. Critical process parameters have been identified to control this phase formation, and therefore, control the 124 intergrowth formation. This work has shown that through process control and proper conductor design, either by adjusting the composition or by multiple coatings of different functional layers, the desired angular dependence can be achieved.
Original language | English |
---|---|
Pages (from-to) | 3347-3350 |
Number of pages | 4 |
Journal | IEEE Transactions on Applied Superconductivity |
Volume | 17 |
Issue number | 2 |
DOIs | |
State | Published - Jun 2007 |
Funding
Manuscript received August 28, 2006. This work was supported in part by the U.S. Department of Energy Office of Electricity Delivery, in part by the Energy Reliability-Superconductivity for Electric Systems, and in part by the U.S. Air Force Office of Strategic Research and DARPA. W. Zhang, Y. Huang, X. Li, T. Kodenkandath, M. W. Rupich, U. Schoop, D. T. Verebelyi, C. L. H. Thieme, and E. Siegal are with American Superconductor Corp., Westborough, MA 01581 USA (e-mail: [email protected]). T. G. Holesinger, B. Maiorov, and L. Civale are with Los Alamos National Laboratory, Los Alamos, NM 87545 USA. D. J. Miller and V. A. Maroni are with Argonne National Laboratory, Argonne, IL 60439 USA. J. Li, P. M. Martin, E. D. Specht, A. Goyal, and M. P. Paranthaman are with Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA. Color versions of one or more of the figures in this paper are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/TASC.2007.899438
Keywords
- Angular dependence
- Coated conductor
- Hybrid
- Intergrowth
- Nanodots
- Pinning
- RABiTS
- RE addition
- YBCO