Modeling of temperature dependent current-voltage curves of YBCO/Ag composites

We have measured the current-voltage (I-V) characteristics of thin film composites made from YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// (YBCO) and Ag. When deposited upon a substrate, this material appears to form arrays of superconducting-normal-superconducting (SNS) junctions. To make these measurements, the films were patterned into microbridges and immersed directly into the cryogen to provide a constant temperature environment and to avoid problems of local heating. The data were fitted by several phenomenological models in an effort to understand the dissipation mechanism appropriate to these materials.