Superconducting thin films of Bi-Pb-Sr-Ca-Cu-O by dc magnetron sputtering from a single target

Superconducting thin films of the Bi--Pb--Sr--Ca--Cu--O system have been prepared on MgO substrates by dc magnetron sputtering from a single sintered target followed by post annealing, in order to examine the effect of Pb addition. The films deposited below 600 deg C are always amorphous and insulating. These films crystallize by high-temperature annealing in air and become superconducting with an onset temperature of 120K. Zero resistivity at 107K appears when the films are deposited at 400 deg C and post-annealed at 850 deg C for 15 h. Although the superconducting properties of the films were quite sensitive to the temperature and duration of the high-temperature annealing step, the growth of the high-T sub c phase in the films is clearly promoted by the addition of Pb. 12 ref.--AA