A sulfurization method for creating the buffer-layers current flow diverter architecture in REBa₂Cu₃O₇ coated conductors

The current flow diverter (CFD) is a known concept that has proven to effectively reduce the probability of destructive hot spots in REBa₂Cu₃O₇ (REBCO; RE = rare earth) coated conductors (CCs) by boosting the normal zone propagation velocity. However, the implementation of the CFD concept requires additional steps in a fabrication process that is already complex and has struggled to find a simple reel-to-reel fabrication method. This work reports on the details of a fabrication route for the buffer-layers-CFD (bCFD) architecture using a solid-vapor silver sulfurization technique to tune the geometry of the metal stabilizer in the high-temperature superconductor tape. The analysis of the microstructure and superconducting properties of the Ag₂S/Ag/GdBCO trilayer processed under different conditions shows how we achieved a new customized functional CC with the bCFD architecture. In DC limitation experiments, this bCFD-sulfide architecture allowed to generate an electric potential much faster than the conventional architecture (60 V s⁻¹ vs. 1.2 V s⁻¹) thanks to the strong enhancement of the NPZV.