Pb-doped Bi-Sr-Ca-Cu-O thin films

Abstract

We prepared Pb-doped Bi-Sr-Ca-Cu-O thin films by rf-magnetron sputtering with multiple targets. A Bi2O3 target compensated for lack of Bi and a PbO target was used to dope Pb into films in sufficient quantity. In thin films, Pb evaporates easily during sintering. We prepared heavily Pb-doped films and they exhibited zero resistance at 94.5 K with sintering as short as 10 min. After 1 h of sintering, more than half of the Pb evaporated and the film showed a sharp transition to its superconducting state. Tce was 106.5 K. Pb doping promotes high Tc phase formation; however, the high Tc phase does not always have to contain Pb.