Abstract: | YBa2Cu3O7−δ (YBCO) based SNS edge junctions with cobalt doped YBCO barriers were prepared and characterized. At 77 K, good junctions had RSJ-like I–V curves with excess current, magnetic suppression of Ic of about 50% or more, and clear microwave steps. The conductance values 1/RN at 77 K of junctions with different barrier thickness and composition, were proportional to the junction areas A, but show little correlation with the thickness of the barriers tB in the range of 15tB100nm. The corresponding IcRN products were observed to scale as J0.66±0.09c, similar to what was found by others. At the same time, the measured values of RN are much smaller than what is expected based on the dimensions of the junction and the resistivity of the barrier material. To explain all of this, we propose a model in which at high supercurrent densities, flux flow of Josephson vortices in the junction leads to RN values which are lower than expected. This model predicts , which fits the observed results very well. |