Development of Fe(Se,Te) Coated Conductors by PLD Process for High Magnetic Field Applications

Abstract

Iron-chalcogenide superconductors are a fascinating group within the family of iron-based superconductors, known for their non-toxic, simple crystal structures, less anisotropy and high critical current density. Fe(Se,Te) films have been realized on flexible metal substrates, and the Fe(Se,Te) coated conductors have high critical current density J _c at 4.2 K under magnetic fields as high as 25 T. This makes them promising for high field applications at liquid helium temperature. For applications, the continuous fabrication of Fe(Se,Te) coated conductors is a key. Here, the Fe(Se,Te) coated conductors were developed through multi-turn pulsed laser deposition on CeO ₂ buffered ion-beam-assisted deposition MgO tape. The effect of parameters on the properties of the Fe(Se,Te) films were systematically studied, such as substrate temperature and target-substrate distance. Under the optimum process, high performance Fe(Se,Te) film was successfully fabricated with critical current density of 0.8 MA/cm ² at 4.2 K and 12 T. So far, 10 m and 100 m class Fe(Se,Te) coated conductors have been successfully fabricated in Shanghai Jiao Tong university. 120 m long FST coated conductor with T _c of about 14 K and J _c of 0.83 MA/cm ² at 4.2 K and 10 T was obtained, which demonstrates the fabrication of long Fe(Se,Te) coated conductor with high performance.