Effect of post-annealing in ar on performance of LRE-Ba-Cu-O single-grain superconductors

Single-grain bulks of Gd-Ba-Cu-O, (SmGd)-Ba-Cu-O and (SmEuGd)-Ba-Cu-O superconductors with high performance were successfully fabricated via two-step cooling method and top-seeded-melt-growth in the ambient atmosphere. The trapped field distributions at 77K were perfect symmetric, and the maximum value of trapped field for (SmEuGd)-Ba-Cu-O sample (018mm) reaches 0.34T, which is comparable with that obtained through OCMG method. The effects of post-annealing in Ar (ArPA) are different for the three LRE-Ba-Cu-O systems. For Gd-Ba-Cu-O system, ArPA cannot improve the superconducting properties. For (SmGd)-Ba-Cu-O and (SmEuGd)-Ba-Cu-O systems, however, their superconducting performances can be enhanced by appropriate ArPA treatment.