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 /s, and the homo-epitaxial layer at a thickness more than 240 nm was deposited at a deposition rate of 30 /s. The resulting CeO ₂ films deposited at 600 °C showed a good texture with a Δ of 5.3°, Δω of 4.2° 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.