Suppression of the critical temperature of superconducting NdFeAs(OF) single crystals by Kondo-like defect sites induced by alpha-particle irradiation

TL;DR

This study investigates how alpha-particle irradiation creates defects in NdFeAs(OF) single crystals, leading to suppression of superconductivity through magnetic and nonmagnetic scattering, with results comparable to MgB2.

Contribution

It reveals the effects of irradiation-induced defects on Tc suppression and identifies Kondo-like scattering as a key mechanism in NdFeAs(OF).

Findings

Irradiation defects cause magnetic and nonmagnetic scattering.

Excess resistance shows Kondo-like ln T behavior.

Tc suppression threshold is similar to MgB2, higher than cuprates.

Abstract

We report a comprehensive investigation of the suppression of the critical temperature Tc of NdFeAs(OF) single crystal by alpha-particle irradiation. Our data indicate that irradiation defects produce both nonmagnetic and magnetic scattering, resulting in the Kondo-like excess resistance $\Delta\rho(T)\propto ln T$ over 2 decades in temperatures above $T_c$. Despite high densities of irradiation defects, the dose at which $T_c$ is suppressed to zero is comparable to that for MgB2 but is well above the corresponding values for cuprates.