Abstract
A reel-to-reel, electron beam evaporation system has been developed to continuously deposit epitaxial CeO2 and other oxide buffer layers on meter long-lengths of rolled Ni tapes. The deposition system includes two interconnected electron beam evaporation chambers and a chamber in which as-rolled Ni tape is in situ annealed to develop biaxial texture. An integral reel-to-reel system with tension control enables motion of the tape with little or no plastic deformation. When depositing epitaxial oxides on Ni, the formation of unfavorably oriented NiO needs to be avoided. Oxide-free, {100}〈100〉-oriented Ni tapes are prepared by control of the partial pressure of H2 during Ni annealing. In situ annealed rolled Ni tape over 70 cm long and 1 cm wide has been deposited with an epitaxial CeO2 buffer layer. Critical current density as high as 700 000 A/cm2 at 77 K in self-field has been achieved for YBa2Cu3O7-x (YBCO) films deposited on short segments of these buffered substrates. X-ray in-plane φ-scans have been performed as a function of length to determine the crystallographic consistency of the epitaxial CeO2 over length. Results of scanning electron microscopy (SEM) examinations of the CeO2 buffer layer microstructure are presented.
Original language | English |
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Pages (from-to) | 27-33 |
Number of pages | 7 |
Journal | Physica C: Superconductivity and its Applications |
Volume | 316 |
Issue number | 1 |
DOIs | |
State | Published - May 1 1999 |
Funding
The authors would like to thank R.A. Hawsey for his support. Three of us (X. Cui, J.E. Mathis and D.T. Verebelyi) would like to acknowledge the support from Oak Ridge Associated Universities. This work was conducted in part under a CRADA with 3M/Southwire/LANL funded by the US Department of Energy, the Office of Energy Efficiency and Renewable Energy, and the Office of Science. Oak Ridge National Laboratory is managed by Lockheed Martin Energy Research for the US Department of Energy under contract #DE-AC05-96OR22464.