Critical currents and pinning mechanism of superconducting Nb-50% wt Ti Alloys

The results of transmission electron microscopy examination as well as the critical current measurements at 4.2K under fields of up to Bc(2) for superconducting Nb-50% wt Ti multifilamentary wire optimized with a new method of multiple heat treatment and processing cycles are presented. The pinning mechanism of the optimized samples is discussed, demonstrating the theoretical basis for the optimization process. In order to improve the T-c of the Nb-50% wt Ti alloys under high fields, we should control the flux shear motion at high fields besides those of both the fine-scale sub-band and alpha -Ti precipitates.