Reel-to-reel continuous deposition of epitaxial CeO/sub 2/ buffer layers on biaxially textured Ni tapes by electron beam evaporation

• Published in: IEEE transactions on applied superconductivity 1999-06, Vol.9 (2), p.1967-1970
• Main Authors: Cui, X., List, F.A., Kroeger, D.M., Goyal, A., Lee, D.F., Mathis, J., Specht, E.D., Martin, P.M., Feenstra, R., Verebelyi, D.T., Christen, D.K., Paranthaman, M.
• Format: Article
• Language: English
• Subjects: Annealing; Buffer layers; Control systems; Crystallography; Electron beams; Microstructure; Motion control; Plastics; Pressure control; Yttrium barium copper oxide
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/77.784847

A reel-to-reel, electron beam evaporation system has been developed to continuously deposit epitaxial CeO/sub 2/ and other oxide buffer layers on meter-long lengths of biaxially textured 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 is difficult to avoid. Oxide free, {100} oriented Ni tapes are prepared by control of the partial pressures of H/sub 2/, H/sub 2/O and O/sub 2/ during Ni annealing. X-ray /spl phi/-scans have been performed as a function of length to determine the crystallographic consistency of the epitaxial CeO/sub 2/ over length. Results of SEM examinations of the CeO/sub 2/ buffer layer microstructure are presented. Results for YBCO films deposited on short segments of these buffered substrates are summarized.