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 double‐sided 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‐δ (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.