Applicability of scaling laws for superconducting critical currents in pseudo-binaries based on Nb₃Ge

Abstract

Pinning forces in chemical-vapour-deposited (CVD) Nb₃Ge₁_ _x M _x pseudo-binaries, where M = Ga or Sn, and 0≤x≤0.02, have been measured as a function of the reduced field. An absence of scaling of the flux-pinning-force density with reduced field is attributed to sample inhomogeneity. The reduced field is re-defined in a way that excludes the very-high-field-critical-current behaviour. Pinning forces as a function of this re-defined field obey a universal scaling law, i.e. the same function describes the normalized pinning for all temperatures and samples.