Neutron Irradiation of Sm-1111

TL;DR

This study investigates the effects of neutron irradiation on SmFeAsO$_{1-x}$F$_x$, revealing increased resistivity, enhanced upper critical field, and improved critical current density, indicating defect-induced modifications in superconducting properties.

Contribution

It provides new insights into how neutron irradiation introduces defects that enhance superconducting performance in SmFeAsO$_{1-x}$F$_x$.

Findings

Resistivity increases due to defect introduction.

Upper critical field is enhanced at low temperatures.

Critical current density within grains improves after irradiation.

Abstract

SmFeAsO$_{1-x}$F$_x$ was irradiated in a fission reactor to a fast (E > 0.1 MeV) neutron fluence of 4x10^${21}$ m$^{-2}$. The introduced defects increase the normal state resistivity due to a reduction in the mean free path of the charge carriers. This leads to an enhancement of the upper critical field at low temperatures. The critical current density within the grains, Jc, increases upon irradiation. The second maximum in the field dependence of Jc disappears and the critical current density becomes a monotonically decreasing function of the applied magnetic field.