In this study, high-entropy type RE123 superconducting thin films were fabricated by FF-MOD method and their properties were evaluated. The definition of a high-entropy RE123 superconductor is that the RE sites of the superconductor are substituted with 5 or more elements, and the proportion of each element is 5-35at%. There are few reports of fabrication of high-entropy RE123 superconductors by the FF-MOD method. High-entropy superconductors are expected to have the strong crystal robustness. Therefore, it is thought that artificial pinning centers can be introduced while maintaining the crystallinity, compared to single RE123 such as Gd123. We have fabricated FF-MOD RE123 films in which the RE site was replaced with five elements of Gd, Sm, Nd, Eu, and Y to prepare a thin film. The nominal composition ratio of the elements was Gd_0.20Sm_0.20Nd_0.20 Eu_0.20Y_0.20Ba₂Cu₃O_y. The critical current density of the film reached over 2.4 MA / cm² at 0 T, 77.3 K. Furthermore, BMO₃-type artificial pinning centers were introduced to improve the critical current density in magnetic fields.

Keywords: RE123, FF-MOD, High-entropy superconductor