High critical current density superconducting tapes by epitaxial deposition of YBa2Cu3O<i>x</i> thick films on biaxially textured metals

TLDR

The authors present a method to produce long, flexible, biaxially textured substrates with smooth, chemically compatible surfaces for epitaxial growth of high‑temperature superconductors. The technique employs scalable thermomechanical processing to biaxially texture a base metal, then vapor‑deposits epitaxial buffer layers to create chemically compatible surfaces. Epitaxial YBa₂Cu₃Oₓ films on these substrates achieve critical current densities exceeding 10⁵ A cm⁻² at 77 K in zero field, with field dependence comparable to single‑crystal ceramic films, indicating the potential for long high‑Jc conductors in high magnetic fields and elevated temperatures.

Abstract

A method to obtain long lengths of flexible, biaxially oriented substrates with smooth, chemically compatible surfaces for epitaxial growth of high-temperature superconductors is reported. The technique uses well established, industrially scalable, thermomechanical processes to impart a strong biaxial texture to a base metal. This is followed by vapor deposition of epitaxial buffer layers (metal and/or ceramic) to yield chemically compatible surfaces. Epitaxial YBa2Cu3Ox films grown on such substrates have critical current densities exceeding 105 A/cm2 at 77 K in zero field and have field dependencies similar to epitaxial films on single crystal ceramic substrates. Deposited conductors made using this technique offer a potential route for the fabrication of long lengths of high-Jc wire capable of carrying high currents in high magnetic fields and at elevated temperatures.