The influence of Cr and Ni impurities on superconducting properties of Nb80Ga20 alloys with A15 type structure

Abstract

The superconducting properties of the Nb80Ga20–xMex (Me = Cr, Ni and 0 ≦ x ≦ 7) alloys are presented. Measurements of the critical temperature Tc, the upper critical field, the magnetization curves, and the normal state magnetic susceptibility and an X-ray analysis are performed. The weak temperature dependence of the magnetic susceptibility as well as the Tc versus impurity concentration dependence suggest that Cr and Ni should be treated as nonmagnetic resonant d-states. [Russian Text Ignored].