Single-domain NEG bulk superconductors for high magnetic field applications

Single-domain (Nd, Eu, Gd)-Ba-Cu-O bulk superconductors, silver free and with 10 wt.% of silver, were prepared with the oxygen-controlled melt-growth process. Seeding techniques were used to promote single-grain growth with controlled orientation using a melt-textured Nd-123 as a seed. The trapped field in the (Nd, Eu, Gd)-Ba-Cu-O bulk of 22 mm diameter and 9 mm thickness was measured at 77 K after field cooled in 7 T. The trapped-field profile was measured by means of a Hall probe at the distance of 5 mm from the sample surface. A single and multiple peaks were observed on (Nd, Eu, Gd)-Ba-Cu-O samples with and without silver addition, respectively. In the sample with silver, a maximum trapped field of 0.5 T was achieved at 3 T after the field reduction from 7 T.