T$_{c}$ suppression in NdFeAs(OF) single crystal by Kondo-like scattering induced by $\alpha $-particle irradiation

We investigated the suppression of $T_{c}$ in a thin NdFeAs(OF) single crystal by uniform disorder induced by irradiation with 2MeV $\alpha $-particles with the fluence up to 5.25$\times $10$^{16}$cm$^{-2}$. Our results indicate that irradiation defects produce both nonmagnetic and magnetic scattering, resulting in a significant Kondo-like excess resistance $\Delta \rho $(T) $\propto $\textit{ lnT} above $T_{c}$ over 2 decades in $T$. Despite very high densities of irradiation defects, the dose at which $T_{c}$ is suppressed to zero is far larger than that required for cuprates and similar to that found for the s-wave two-band superconductor MgB$_{2}$. The observed resilience of multiband superconductivity in pnictides to strong magnetic and nonmagnetic disorder presents a challenge to the existing theories.