Fabrication of Long Lengths of Epitaxial Buffer Layers on Biaxially Textured Nickel Substrates Using a Continuous Reel‐to‐Reel Dip‐Coating Unit

Abstract

A low-cost, nonvacuum, solution precursor route has been developed to produce epitaxial oxide buffer layers of Eu 2 O 3 or La 2 Zr 2 O 7 on biaxially textured Ni (100) tapes. A reel-to-reel continuous dip-coating unit consisting of a constant-tension tape transport system attached to a controlled atmosphere furnace was fabricated. Nickel tapes were pulled through a 2-methoxyethanol solution of europium methoxyethoxide/acetate or lanthanum zirconium methoxyethoxide. The doublesided dip-coated tapes were then annealed in a preheated furnace at 1000°-1100°C with a high flow rate of Ar/H 2 (4%) gas. The dip-coated buffers were dense, continuous, crack-free, and epitaxial with a single cube texture. A critical current (J c ) of >1 MA/cm 2 at 77 K and self-field was obtained for YBa 2 Cu 3 O 7-␦ (YBCO) films with a layer sequence of YBCO (ex situ BaF 2 process)/CeO 2 (sputtered)/YSZ (sputtered)/ Eu 2 O 3 (dip-coated)/nickel. We have produced 1-2 m lengths of epitaxial buffer layers on textured nickel substrates using a nonvacuum process for the first time.

Deposition of rare earth tantalate buffers on textured Ni-W substrates for YBCO coated conductor using chemical solution deposition approach

“…23 Here, we report the successful growth of textured film of rare earth tantalates, RE 3 TaO 7 on Ni-W substrates, its texture and micro-structural analysis for the first time. Various rare-earth oxides [24][25][26][27] and rare-earth pyrochlores 28,29 films have been grown epitaxially on biaxially textured Ni and Ni-3 at.% W (Ni-W) substrates by solution based methods as buffer layers for YBCO coated conductors. Since, we demonstrated previously that RE 3 NbO 7 23 can be used as a single buffer layer for YBCO coated conductor, we believe that the solution deposited RE 3 TaO 7 films with good epitaxy are potential candidates which can be used as a single buffer layer in RABiTS architecture.…”

Assessment of Chemical Solution Synthesis and Properties of Gd2Zr2O7 Thin Films as Buffer Layers for Second-Generation High-Temperature Superconductor Wires

“…1-3 Moreover, non-vacuum based chemical solution deposition processes such as sol-gel, chelate, and/or metalorganic decomposition (MOD) have proven to be a viable low-cost high-volume manufacturing technology for long-length practical wires. 5,6 Solution chemistry has the advantage of atomic-scale mixing of species, precise control of metal-oxide precursor stoichiometry, as well as near 100% utilization of the precursor material.…”

“…4,7,8 Recently, there have been significant efforts concentrated on chemical solution derived SrTiO 3 , RE 2 O 3 , RE 2 Zr 2 O 7 , and RE 3 NbO 7 (RE ‫ס‬ rare-earth) films to assess their feasibility as buffer layer materials on RABiTS. 6,[9][10][11][12][13] Among these systems, sol-gel processed single La 2 Zr 2 O 7 (LZO) buffer layers, a RE 2 Zr 2 O 7based cubic pyrochlore structure, as well as LZO seeds capped with sputtered CeO 2 /YSZ layers have shown the most promise as templates for YBCO with high-J c performance. 10,14 Despite similar precursor processing chemistries, the other solution based material systems have not yet demonstrated performance levels as effective as RE 2 Zr 2 O 7 .…”

Nitrate-based metalorganic deposition of CeO2 on yttria-stabilized zirconia

“…Most researchers have chosen to use dry Ar/H 2 mixtures to create a strongly reducing atmosphere. 2,[5][6][7][8][9] The oxygen required for the formation of CeO 2 can either come from latent moisture in the gas bottle or from the decomposition of the organic ligands, such as acetylacetonate, that contain oxygen. A consequence of maintaining this very low P(O 2 ) is that it is difficult to remove carbon.…”

“…6 Many other solution techniques for the production of YBCO buffer layers exist, using many metalorganic compounds to produce a wide variety of oxide layers. [2][3][4][5][6][7][8][9][10][11] A nitrate-based solution was used to grow CeO 2 on yttria-stabilized zirconia (YSZ) substrates in this study. Nitrate-based solutions have proved to be successful in growing oxide thin films.…”