Surface resistance of Bi-2212 films fabricated by multitarget sputtering

We investigated the surface resistance of Bi-2212 films fabricated by the multitarget sputtering method. The surface resistance was not dependent on the product of the grain size and the critical current density, although many high temperature superconductors such as Y-Ba-Cu-O agree with such a weak-link model. Therefore, it is possible that the conduction losses are relatively low at grain boundaries in Bi-Sr-Ca-Cu-O. On the other hand, it was found that the intergrowth of Bi-2212 with Bi-2201 or Bi-2223 influenced the surface resistance badly. This is very interesting, although it has never been clarified as to why the surface resistance is dependent on the intergrowth. Further study will be required in order to interpret the behavior of the surface resistance of BSCCO.