Characterization of thin film composite mixtures of Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7-/spl delta// and Y/sub 2/O/sub 3/

In our studies of the behavior of materials forming thin film composites with Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7-/spl delta// (YBCO), we have characterized thin film composite mixtures of YBCO and Y/sub 2/O/sub 3/ (yttria) grown onto (100) MgO and (100) SrTiO/sub 3/ substrates by off-axis sputtering. We have examined the transport properties of the films, in particular the critical current density, J/sub c/. The temperature dependence of J/sub c/ for composites on SrTiO/sub 3/ is identical to that of our pure YBCO films, while for composites on MgO the J/sub c/ is similar to measurements on our earlier composites of YBCO and Y/sub 2/Ba/sub 1/Cu/sub 1/O/sub 5/ ("211"). The field dependence of J/sub c/ for the YBCO/yttria composites is different from our pure YBCO films, and from our earlier composites, but the magnitude of the flux pinning is similar.<
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