Further Increase of T c in Y-Ba-Cu-O Superconductors

This paper presents the synthesis and characterization of three new Y-based high temperature-superconducting compounds having relatively higher transition temperature T _c compared with that of the Y-123, Y-124, and Y-247. The electrical resistivity measurements indicate the onset critical temperatures as high as 98 K. Atomic compositions of these new Y-Ba-Cu-O superconductors are Y₂Ba₃Cu_5.2O _x , Y₂Ba₅Cu₉O _x , and YBa₄Cu₅O _x . The X-ray analysis has shown that they have a similar crystalline structure as Y-123 phases.