Fabrication of Thick YBa ₂ Cu₃O₇ Film on Ni-electroplated Cu/SUS316 Laminated Tape

Abstract

The authors tried to install CeO ₂/YSZ/CeO₂ buffer layers, where the thicknesses of the CeO ₂ (seed and cap layers) and YSZ were 80, 40 and 260 nm, for a 1 μm-thick YBCO (YBa ₂ Cu₃ O₇)-coated conductor using Ni-electroplated {100}<001> textured Cu/SUS316 laminated tape. We found that oxygen from the atmosphere permeated through the buffer layers to the Cu tape surface during deposition of the 1 μm-thick YBCO layer, and that the diffused oxygen reacted with the Cu on the Cu tape surface. This resulted in the generation of a thick Cu-oxide layer between the CeO₂ seed layer and the Cu tape, and thereby caused delamination of the buffer layers and/or YBCO layers. To prevent delamination, the deposition time was shortened. The J_c of the 1 μm-thick YBCO film prepared on the CeO ₂ /YSZ/CeO ₂ -buffered Ni-electroplated {100}<001> textured Cu/SUS316 laminated tape reached 1.5 MA/cm² at 77 K in the self magnetic field.