Development on Process for Producing Continuous Fine Diameter Filaments of Superconductors

A process to produce the continuous niobium carbonitride filament yarn from both carbon and boron nitride precursors was developed. The process involved converting chemically the precursor yarns into niobium carbonitrides with niobium pentachloride in the presence of hydrogen and nitrogen. The superconductive filament yarns produced were characterized by their superconducting and mechanical properties and their surface structures. Critical temperatures up to 19 K were observed for the superconductive filaments made by this method. The critical currents of some of the filaments were determined to be 0.4-1.0 x 10 to the 5th power ampsq cm in zero field. Procedures to prepare filaments with high flexibility and strength were also developed.