Critical Magnetic Fields of High-Field Superconductors

Abstract

The critical magnetic fields ${\text{H}}_{{\text{K}}_2 }$ and the field corresponding to the initial penetration of the magnetic flux ${\text{H}}_{{\text{K}}_1 }$ are measured for the intermetallic compounds Nb₃Sn and V₃Ga and worked Nb-Ti and Nb-Zr-Ti alloys. The relation between ${\text{H}}_{{\text{K}}_1 }$ and the state of the alloys is studied. The field corresponding to the penetration of magnetic flux increases with increasing inhomogeneity of the sample and equals about ${10^{ - 2}}{H_{{K_2}}}$.