48 research outputs found
Direct fabrication of high-quality ring-shaped REBa2Cu3Oy bulk magnets by the Single-Direction Melt Growth (SDMG) method
Ring-shaped REBa2Cu3Oy melt-textured bulks have been successfully grown by
the Single-Direction Melt Growth (SDMG) method, which enables the direct
fabrication of uniform bulks with high reproducibility. Three homogeneous
DyBa2Cu3Oy ring-bulks with various sizes were synthesized in this study. All of
these bulks exhibited concentrically cone-shaped trapped field distribution on
the surface and high trapped field more than 1.8 T at 77 K inside the ring, the
highest among bulks of comparable size to date. Furthermore, superconducting
properties such as superconducting transitions and critical current densities
are highly uniform throughout the bulk, confirming the effectiveness of the
SDMG approach. Our findings represent a significant advancement in the direct
fabrication of high-quality ring-shaped REBCO bulks suitable for high magnetic
field applications, in particular, compact nuclear magnetic resonance systems.Comment: 4 pages, 4 figuers, 1 tabl
Development of homogeneous and high-performance REBCO bulks with flexibility in shapes by the single-direction melt growth (SDMG) method
We have developed a single-direction melt growth method in which REBCO
melt-textured bulks grow only vertically from a seed plate utilizing the
difference in peritectic temperatures of REBCO. Entirely c-grown YBCO, DyBCO
and GdBCO bulks with various sizes and shapes were successfully fabricated with
high reproducibility. Disk-shaped bulks showed high trapped fields with almost
concentric field distributions, reflecting homogeneous and boundaryless bulky
crystal. In particular, a YBCO bulk with a 32 mm diameter trapped a high field
more than 1 T at 77 K. Furthermore, rectangular and joined hexagonal REBCO
bulks were successfully fabricated, showing designed field-trapping
distributions reflecting their shapes through well-connected superconducting
joints among bulks.Comment: 8 pages, 6 figures, 2 table