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AFM analysis of step-edge Josephson junctions

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Abstract

We report on an analysis of step-edge Josephson junctions with a variety of different electrical behavior I<sub>c</sub>'s and IV curve characteristic shapes. We investigated a correlation between the shape of the IV curve and the morphology of the step-edge YBCO film concentrating on the sharpness of the step. Using Atomic Force Microscopy (AFM), determination of the film's surface properties over the step were obtained. The steepness of the angle of the film over the step correlated with the behavior of the IV curve. When the average angle over the step was >23° the IV curve exhibited the resistively shunted junction [RSJ] shape. Less steep average angles <23° corresponded to flux flow-like IV curves

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