Preparation of Ag-Sheathed (Tl, Bi)-Ca-Sr-Cu-O Superconducting Wire

In the Tl-Bi-Ca-Sr-Cu-O system, Tl-O single layered superconducting phases of (Tl, Bi)CaSr2Cu2O x and (Tl, Bi)Ca2Sr2Cu3O x have been obtained. We prepared Ag-sheathed wire using the oxide powder of the (Tl, Bi)Ca2Sr2Cu3O x phase with T c of 113 K. With a decrease in the thickness of the rectangular wire specimen, J c at 77 K increases rapidly, reaching a maximum value of 1.45×104 A/cm2 at 0.05 mm in thickness. The crystal structure, morphology and microstructure of the superconducting core of the wire were observed using XRD, SEM and TEM to investigate the cause of the J c enhancement.