Particle and γ Ray Irradiation on CaKFe 4 As 4 : Effect on Critical Current Density

We investigate the impact of proton, Xe ion, and gamma-ray irradiation on the critical current density components in the singe-crystal iron-based superconductor CaKFe₄As₄ In particular, we investigate via magnetic measurements the in-plane critical current densities for fields applied along the c axis (Jc) and parallel to the ab plane Jcab. This 1144-type compound, known for its high Jcand anisotropic pinning behavior, exhibits a complex vortex pinning landscape. By comparing pre- and post-irradiation behavior under magnetic fields applied parallel and perpendicular to the irradiation direction, we assess the effectiveness of different defect types as pinning centers. Our results provide insights into how irradiation type influences Jcanisotropy and its field dependence, with implications for conductor development.