Estimate of density-of-states changes with disorder inA−15superconductors

Abstract

Data are presented which show that the density of states changes dramatically, as does $T_c$, in both ${\mathrm{Nb}}_3$Sn and ${\mathrm{Nb}}_3$Ge samples which were disordered by $\alpha$-particle irradiation. The density of states is derived from the strong-coupling modifications to the theory of type-II superconduction along with measurements of ${\left(\frac{d{H}_{c2\mathrm{}}}{\mathrm{dT}}\right)}_{\mathrm{Tc}}$ and the residual normal-state resistance ${\rho }_0$.