We have studied the critical temperature $T_c$, upper critical field, and magnetotransport variation as a function of radiation damage in the low-$T_c$ A15 superconductor ${\mathrm{Nb}}_3$Ir. We find a nonmonotonic variation in $T_c$ with disorder and analyze these results in terms of the competition between density-of-states effects and weak localization. Magnetoresistance measurements confirm the presence of electron interaction effects associated with weak localization.

• Received 29 December 1986

DOI:https://doi.org/10.1103/PhysRevB.35.8405