Superconductivity at High Magnetic Fields and Current Densities in Some Nb-Zr Alloys

Abstract

The results on Nb-Zr alloys were obtained during investigation of resistive superconducting transitions in certain Ti-, Zr-, Nb-, Hf-, and Ta-rich lunary alloys in magnetic fields up to 30 kgauss. The data show that cold-worked Nbrich Nb-Zr alloys display zero electrical resistance at current densities as high as 10/sup 5/ amp/cm/sup 2/ at 30 kgauss and at 4.2 deg K. Present measurements reveal high-field superconducting effects in cold-rolled Nb-Zr alloys such as a marked dependence of the magnitude of the maximum zeroresistance current upon the direction of the externally applied transverse magnetic-field rehative to the rolled surface of the specimen, and anomalous increase of the maximum zero-resistance current with increase of magnetic field strength over certain regions in certain alloy specimens. The source materials, method of fabrication, and cross-sectional dimensions of the specimens are given. (P-C-H- )