Relationship between critical current properties and microstructure in cylindrical RE 123 melt-solidified bulks

We report the synthesis of cylindrical melt-solidified bulks in REBa2Cu3Oy (RE = Sm, Gd, Dy, Ho, Y and Er), and their critical current properties and microstructures of the a- and the c-growth regions. It was found from the microstructure analysis that the volume fractions of RE211 particles in the c-growth region were always lower than those in the a-growth region. Moreover, those in the c-growth region were increased with distance from the seed crystal. Interestingly, the second peak effects in Jc-B curves were prominently enhanced for the c-growth region. Jc values at zero field for the c-growth region through the appropriate oxygen post-annealing reached approximately 95 kA CM -2 for RE = Ho, Dy and Y.