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.