# Using electron irradiation to probe iron - based superconductors

## TL;DR

This paper reviews how high-energy electron irradiation creates controlled defects in iron-based superconductors, enabling phase-sensitive tests that support the sign-changing s_{±} pairing symmetry.

## Contribution

It provides a comprehensive review of electron irradiation effects as a probe for superconducting pairing symmetry in iron-based superconductors.

## Key findings

- Electron irradiation introduces non-magnetic scattering centers.
- Irradiation supports the sign-changing s_{±} pairing model.
- Phase-sensitive measurements confirm pairing symmetry insights.

## Abstract

High energy electron irradiation is an efficient way to create vacancy-interstitial Frenkel pairs in crystal lattice, thereby inducing controlled non-magnetic point - like scattering centers. In combination with London penetration depth and resistivity measurements, the irradiation was particularly useful as a phase - sensitive probe of the superconducting order parameter in iron - based superconductors lending strongest support to sign - changing $s_{\pm}$ pairing. Here we review the key results on the effect of electron irradiation in iron-based superconductors.