Y1Ba2Cu3O7−x and LaAlO3 composite thin films by off-axis magnetron sputtering

Thin-film composites of co-sputtered Y1Ba2Cu3O7−x and LaAlO3 have been deposited by off-axis magnetron sputtering. Scanning electron microscopy (SEM) and x-ray diffraction studies suggest that LaAlO3 precipitates along the grain boundaries of the Y1Ba2Cu3O7−x grains. The normal state conductivity, transition temperature, and critical current density systematically decreased with increasing LaAlO3 composition, consistent with a decrease in the coupling between Y1Ba2Cu3O7−x grains. Inductive transition widths were only a few degrees wide for all LaAlO3 compositions, indicating homogeneous materials. Initial photoresponse measurements show bolometric behavior near Tc and increased response for greater LaAlO3 compositions.