Spatial investigation on structural properties of GdBa₂Cu₃O_{7 - X} coated conductors grown on IBAD-MgO based stainless-steel substrates

The performance of high-temperature superconducting (HTS) wires has been studied for various substrates and buffer layers. Progress is still being made to find new materials for use as superconducting layers, buffer layer, and substrates for HTS wires. Therefore, it is important to investigate the stacking structure of the commercial wires to improve their performance. Among the commercial wires, GdBCO coated conductors on stainless-steel (STS) were studied in this paper. STS can be purchased at a competitive price, and therefore it is a promising substrate for use in second generation (2G) HTS wires. To analyze structural properties of the GdBCO coated conductors on the STS substrate, several characterization tools are used. Scanning transmission electron microscopy (STEM) with energy dispersive spectroscopy (EDS) was used to investigate microstructure of films. In addition, we performed scanning laser microscopy on the conductors at room temperature to identify a map of the inhomogeneity positions. Raman scattering spectroscopy was also used to identify the secondary phases and to verify the phase formation in the films. The results of the analysis revealed the features of GdBCO coated conductors on STS for progress of HTS wires used particularly in rotating machines for high magnetic field applications.