Niobium-titanium superconducting wires with ultrafine filaments (A role of SC filament-matrix boundaries)

The influence of boundaries in superconducting Nb-Ti filaments in a Cu matrix upon critical current density and upper critical magnetic field is presented. The copper-matrix wires 25000 and 480000 Nb-Ti filaments. The wires were manufactured by cold deformation without any annealing. It was found that the current-carrying capacity and the magnetic hysteresis curve of these ultrafine-filament wires are determined by the fluxoid pinning on the Nb-Ti filament-matrix boundaries. The pinning can be reduced by interdiffusion of Cu and Ti.<
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