A Method to Enhance Thickness and Current-Carrying Capacity of BZO-Doped YBCO Multilayers

This study demonstrates a significant enhancement in the in-field critical current density and its isotropy in BZO-doped YBCO multilayer structures, achieved through improvements in the crystalline quality of YBCO, which extend the electron mean free path. The incorporation of undoped YBCO, alongside alternating BZO-doped and Ca-doped YBCO layers, revealed that the Ca-doped intermediate layer positively influenced the interface quality, promoting better growth in the subsequent layers. These improvements also enabled an increase in total film thickness, thereby enhancing the current-carrying capacity. Furthermore, the paper discusses the mechanisms behind these enhancements and presents a model explaining how nanorod pinning centres in different layers affect vortex pinning behavior. These insights offer valuable guidance for designing future YBCO coated conductor structures.