Robustness of superconductivity to competing magnetic phases in tetragonal FeS

TL;DR

This study investigates the superconducting and magnetic properties of tetragonal FeS, revealing that superconductivity remains robust despite variations in magnetic phases, with implications for understanding magnetic effects in superconductors.

Contribution

It provides new insights into the coexistence and robustness of superconductivity in FeS despite sample-dependent magnetic variations, using muon spin rotation measurements.

Findings

Superconductivity in FeS shows fully gapped behavior with a penetration depth of 204 nm.

Presence of a small magnetic phase varies between samples but does not affect superconductivity.

Superconducting properties are remarkably insensitive to magnetic phase variations.

Abstract

We have determined the superconducting and magnetic properties of a hydrothermally synthesized powder sample of tetragonal FeS using muon spin rotation ({\mu}SR). The superconducting properties are entirely consistent with those of a recently published study, showing fully gapped behavior and giving a penetration depth of {\lambda}_{ab} = 204(3) nm. However, our zero-field {\mu}SR data are rather different and indicate the presence of a small, non-superconducting magnetic phase within the sample. These results highlight that sample-to-sample variations in magnetism can arise in hydrothermally prepared phases, but interestingly the superconducting behavior is remarkably insensitive to these variations.