Morphology of barrier layer formed on YBCO

The morphology of barrier layers, such as LaSrGaO/sub 4/ (LSGO) and SrTiO/sub 3/ (STO), was investigated using an atomic force microscope (AFM) and tunnel junctions with an Au/barrier/YBCO layered structure. The barrier morphology depended strongly on both the surface roughness of YBCO films and the deposition temperature of the barrier materials. It was improved by reducing the surface roughness of the YBCO films and keeping the deposition temperature lower than 400 degrees C during the barrier formation. The experiments performed are described, and the results are presented and discussed.<
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