[WBP1] Conductor Processing & Evaluation

[WBP1-05] High-performance FeSeTe superconducting films: Controllable fabrication and performance enhancement

*Jixing Liu¹, Botao Shao¹, Shengnan Zhang¹, Jianfeng Li¹, Pingxiang Zhang¹ (1. Northwest Institute for Non-ferrous Metal Research (China))

Keywords:

iron-based superconductor,FeSeTe,film,flux pinning

Iron-based superconducting materials have garnered significant attention for practical applications since their discovery in 2008, owing to their high upper critical fields and low anisotropy. They have now become a primary target for developing next-generation practical superconductors. Among these materials, FeSeTe superconducting films demonstrate exceptional promise, maintaining critical current densities exceeding 10⁵ A cm^-2under high-field conditions of 4.2 K and 30 T. This positions FeSeTe as a highly viable practical superconducting material, offering new possibilities for high-field magnet technology development. However, the complex phase formation and presence of low-melting-point elements in FeSeTe result in low phase purity and density in sputtering targets, severely compromising the performance stability of the derived films. To address this, we developed a high-pressure sintering process for fabricating FeSeTe targets with high phase purity and density. Subsequently, we optimized key pulsed laser deposition parameters to produce FeSeTe superconducting films with controlled composition and superior performance, achieving consistently high critical temperatures above 21 K. Furthermore, by implementing electron doping in the target material and superlattice modulation, we enhanced both the superconducting properties and flux pinning capabilities of the films. This improvement is attributed to increased carrier concentration and strain effects induced by interfacial phenomena associated with the superlattice.