This paper describes the preparation of the high Tc Y–Ba–Cu–O system superconducting filaments utilizing a low cost textile fiber spinning technology for alumina fiber. Two precursor techniques of a spinning of viscous solution and an extrusion of slurry were examined for the formation of long filaments. The precursor to the Y–Ba–Cu oxide containing poly(vinyl alcohol) (PVA) was extruded as a filament, dried and subjected to heat treatment to remove volatile components and to generate the oxide in the appropriate phase and grain size. The long filament more than 20 µm in diameter was obtained and was a polycrystalline with grain size of 200–400 nm and had a layered perovskite structure. The filaments were so brittle that they were pressed into a pellet and the Tc of the pellet was measured by the resistive method. The onset temperature was observed at 90.5 K and a zero resistivity state at 85.4 K.

Gotō, T., Horiba, I., Kada, M., & Tsujihara, M. (1987). Preparation of High Tc Oxide Superconducting Filaments Using the Method of Solution Spinning. Japanese Journal of Applied Physics, 26(S3-2), 1211.