THIN-FILM COMPOSITES OF AU AND YBA2CU3O7-DELTA

Using a novel bilayer deposition process, we have grown composite films of Au with YBa2Cu3O7-δ on various substrates. Our composites have well-segregated regions of Au and YBa2Cu3O7-δ, and we have not observed structural degradation of the grains or grain boundaries in the films. Transition temperatures and critical current density measurements have behaviors consistent with regions of weakened grain boundary coupling in the films. Photoresponse measurements are also reported. We believe that Au is diffusing into the grain boundaries and weakening the coupling between YBa2Cu3O7-δ grains. By varying the amount of Au in the films, the coupling can be adjusted. These Au/YBa2Cu3O7-δ composite films are promising materials for device applications relying on vortex motion.