Long length coated conductors (CCs) have recently become commercially available, serving as a promising candidate for use in electric power applications. However, the cost of materials and manufacturing is high, which discourages their use in widespread commercially feasible products.REBa 2 Cu 3 O 7 (REBCO; RE: Y or rare earth elements) superconducting films with high critical current density ( J c ) have been grown on cube textured metal tapes for the purpose of developing CCs for high temperature, high magnetic field applications. In the standard approach, a biaxially crystal aligned YBCO layer is deposited on a Y 2 O 3 /Y 2 O 3 stabilized ZrO 2 /CeO 2 buffered Ni W tape. CCs become highly resistive when they are quenched, therefore, to manufacture reliable and safe applications, it is necessary to attach low resistive metal layers such as Cu and/or Ag to the CCs to stabilize and protect from damage due to quenches. Presently, insulative oxides are used for the buffer layers, thus thick Ag and Cu layers are required to be deposited as the stabilizer layers on the YBCO layer. However, the high material and process costs for the Ag and Cu layers are one of the major obstacles for achieving low cost CCs. Use of conductive buffer layers instead of the insulative ones will allow CCs to be less expensive. In this paper, we propose a new configuration for CCs: YBCO deposited on a conductive Sr(Ti 0.95 Nb 0.05 )O 3 buffered Ni electroplated {100} 〈001〉textured Cu and SUS316 lamination tape. Sr(Ti 0.95 Nb 0.05 )O 3 was epitaxially grown on the Ni electroplated {100} 〈001〉textured Cu tape and its resistivity was low as 2.5 mQ cm at 77 K. Excellent J c of 2.6×10 6 A/cm 2 was achieved at 77 K under a magnetic self field for the YBCO/Sr(Ti 0.95 Nb 0.05 )O 3 /Ni/Cu/SUS316 tape. We believe that Sr(Ti 0.95 Nb 0.05 )O 3 is one of promising candidates for the conductive buffer layer material.
Cube-textured Cu tape is highly desirable as a substrate for practical superconducting wires operating in the liquid nitrogen temperature regions, because not only is Cu a non-ferromagnetic metal, the material cost is also much cheaper than Ni or Ni-based alloys. The primary disadvantage, however, is that Cu has poor resistance to oxidation in an oxygen atmosphere at high temperature during the fabrication of YBCO. We therefore added a Ni overlayer on top of the {100}<001> textured Cu tape by electroplating, to reduce the oxidation rate of the Cu substrate. We successfully obtained biaxially oriented YBCO films with a critical current density (J c) over 4.5 MA/cm 2 in a self-field at 77 K on cube-textured Cu tapes using CeO 2 /YSZ/CeO 2 /Ni buffer layers.
Synopsis:The authors tried to install CeO 2 /YSZ/CeO 2 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 Cu 3 O 7 )-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 CeO 2 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/cm 2 at 77 K in the self magnetic field.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.