Greatly Improved Trapped Magnetic Fields of REBCO Melt-Grown Bulks Through Reductive High-Temperature Post-Annealing

We investigated the effects of high-temperature post-annealing on magnetic field-trapping properties of REBa2Cu3Oy melt-grown bulks composed of a single c-growth domain prepared by the single-direction melt growth (SDMG) method. High-temperature post-annealing at 900 ? under moderately reductive atmosphere for readily oxygenated bulks greatly improved trapped fields with maintaining circular concentric distributions. Oxygen diffusion was found to be further accelerated after post-annealing as well. An enhancement ratio of the trapped field averaged over all bulks through this post-annealing was similar to 40% in the present study. In particular, a DyBa2Cu3Oy bulk with 24.3 mm in diameter and 10.8 mm in thickness recorded a high trapped field of 1.09 T at 77 K.

Automated summary

The effects of high-temperature post-annealing on the magnetic field-trapping properties of REBa2Cu3Oy melt-grown bulks were investigated. The post-annealing greatly improved the trapped fields and accelerated oxygen diffusion in the bulks. The trapped field enhancement ratio averaged over all bulks was about 40%, and a DyBa2Cu3Oy bulk recorded a high trapped field of 1.09 T at 77 K.