High critical current density superconducting tapes by epitaxial deposition of YBa₂Cu₃O_x thick films on biaxially textured metals

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 surface. Epitaxial YBa₂Cu₃O_x 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 substrate. Deposited conductors made using this technique offer a potential route for the fabrication of long lengths of high-J_c wire capable of carrying high currents in high magnetic fields and at elevated temperatures.