Improving the microstructure and levitation performance of YBa₂Cu₃O₇₋ _δ bulks with combined-modified precursor powder for HTS maglev

Abstract High-temperature superconducting (HTS) pinning magnetic levitation (Maglev) vehicles employ HTS bulk superconductors to achieve its unique levitation and guidance feature above the track, making it a promising Maglev vehicle system. However, few studies consider customizing HTS bulk superconductors for a specific application, particularly in the HTS Maglev system, which hinders its development. In this study, a novel approach is introduced, in which the combined-modified precursor powder (C-MPP) is used to enhance the mechanical and superconducting properties of YBa 2 Cu 3 O 7− δ (YBCO or Y123) bulks, which are crucial for HTS pinning Maglev system. The C-MPP method integrates conventional precursor powder (CPP) with MPP in a layered configuration. The large-size YBCO bulks prepared by C-MPP reveal that C-MPP samples exhibit reduced deformation and shrinkage compared to MPP, and alleviate the issue of high porosity. Levitation force measurements indicate that C-MPP can provide superior superconducting properties over CPP. Additionally, in consideration of the realistic application settings, a general method is proposed for comparing the levitation force across samples of different sizes, providing a valuable methodology for evaluating the potential of HTS bulks for researchers and engineers. The findings suggest that the C-MPP technique represents a viable advancement for enhancing the efficiency and reliability of the HTS pinning Maglev system in future high-speed transit solutions.