A study on CeO₂ buffer layer on biaxially textured Ni-3%w substrate deposited by electron beam evaporation with high deposition rate

CeO₂ has been widely used for single buffer layer of coated conductor because of superior chemical and structural compatibility with ReBa₂Cu₃07-δ(Re=Y, Nd, Sm, Gd, Dy, Ho, etc.). But, the surface of CeO₂, layer showed cracks because of the large difference in thermal expansion coefficient between metal substrate and deposited CeO₂layer, when thickness of CeO₂ layer exceeds 100 nm on the biaxially textured NL3%W substrate. The deposition rate has been limited to be less than 6 A/sec in order to get a good epitaxy. In this research, we deposited CeO₂ single buffer layers on biaxially textured Ni-3%W substrate with 2step process such as thin nucleation layer(>10 nm) with low deposition rate(3 Å/sec) and thick homo epitaxial layer(>240 nm) with high deposition rate(30 Å/sec). Effect of deposition temperature on degree of texture development was tested. Thick homo epitaxial CeO₂ layer with good texture without crack was obtained at 600 °C, which has Δφ A<j) value of 6.2 °, Δω value of 4.3 and average surface roughness(Ra) of 7.2 nm within 10 μm × 10 μm area. This result shows the possibility of preparing advanced Ni substrate with simplified architecture of single CeO₂ layer for low cost coated conductor.