部分溶融成長法によるRE-Ba-Cu-O接合バルク超伝導体の作製とパルス着磁挙動の評価

抄録

Conditions for obtaining high-quality joined bulk superconductors using the local melt-growth method with sintered Er-Ba-Cu-O as the joining material for Gd-Ba-Cu-O melt-grown bulk superconductors and the effect of applying pulse field magnetization （PFM） to the joined superconductor were investigated. The effects of important melting conditions of the local melt-growth method on microstructure and superconducting properties were clarified, and it was confirmed that a lower maximum temperature, shorter holding time at maximum temperature, and faster cooling rate can obtain a good quality microstructure and improve superconducting properties. Next, measurements of magnetic field behaviors when PFM was applied revealed that the joined part of the joined bulk superconductor is the preferential field penetration path. A single peak with a maximum trapped field of 0.52 T was obtained at above 4 mm from the sample magnetized at an applied field of 5.0 T at 50 K by PFM. Finally, the PFM was simulated by FEM analysis to confirm the details of the thermal and magnetic field behavior, which confirmed that the joined part is the preferential field penetration path as in the actual experiment. This could contribute to the development of superconducting joining technology, which is an important key to the technology in the larger bulk superconductors, and could make pulse magnetization an efficient method of magnetization.