Fabrication of CeO2 buffer layer with high deposition rate on biaxially textured Ni–3%W substrate by electron beam evaporation

CeO2 has been used as a buffer layer of a coated conductor because of good chemical and structural compatibility with YBCO. But cracks were often observed at the surface for films thicker than 100 nm deposited at a high temperature because of a large difference in a thermal expansion coefficient between metal and CeO2. The deposition rate was limited to be slow for getting good epitaxy. In order to increase the film deposition rate, while maintaining the epitaxy till a final thickness, two-step deposition process was tested. The thin seed layer with a thickness less than 10 nm was deposited with a deposition rate of 3 angstrom/s, and the homoepitaxial layer at a thickness more than 240 nm was deposited at a deposition rate of 30 angstrom/s. The resulting CeO2 films deposited at 600 degrees C showed a good texture with a Delta phi of 5.3 degrees, Delta omega of 4.2 degrees and Ra of 2.2 nm. The two-step process may be option for a low cost buffer layer for Ni-3%W metal substrates for the coated conductor. (C) 2011 Elsevier B.V. All rights reserved.