Formation of artificially layered superconducting Bi-Sr-Ca-Cu-O thin films by multitarget sputtering

Abstract

Thin films of the Bi-Sr-Ca-Cu-O system have been prepared by the sequential deposition of Bi, SrCu, CaCu oxides using a multitarget dc magnetron sputtering at substrate temperatures lower than 650°C. It was revealed that the number of Cu-O planes of the crystal structure was controlled by varying the deposition time of CaCu oxide. We have successfully prepared the Bi-Sr-Ca-Cu-O films with four and five Cu-O planes. However these films did not show a superconducting onset temperature above 100 K. It was revealed that the superconducting temperature in the Bi system is not ruled by the number of Cu-O planes.