Superconducting transitions of Nd-based 123 superconductors in fields up to 7 T

Superconducting transitions were measured in field-cooled cooling and field -cooled warming modes in external magnetic fields ranging between 1 mT and 7 T on various Nd-based 123 superconductors (NdBa2Cu3O7-delta single crysta ls and melt-processed samples, and melt-textured ternary compounds). Most o f the Nd-based superconductors investigated exhibit a two-step transition w hen being cooled or warmed in fields larger than 4 T. We ascribe this effec t to the presence of an Nd-rich phase providing a spatial scatter of the tr ansition temperature, T-c, throughout the sample.