Enhancement of critical current density and reduction of proximity coupling in fine filamentary NbTi with Si and Mn alloyed Cu matrices

Critical current density J_c and magnetization data are given on fine filamentary NbTi materials with a series of different copper alloy matrices containing Si, Mn, or both. By applying the correct thermomechanical treatment, materials of this type can give high J_c´s with minimal electrical coupling. The use of Si has a particular advantage in that it greatly reduces intermetallic compound formation and may, therefore, obviate the need for a barrier around the filaments under certain conditions