Sputter deposition of oriented Y-Ba-Cu-O thin films and study of grain boundary Josephson junctions

Superconducting thin films of Y-Ba-Cu-O were prepared using high pressure (⪖ 100 mTorr) rf magnetron sputtering. The resputtering effects due to presence of negative ions were almost eliminated. The films grown on (100)SrTiO 3 were highly a-axis oriented while films grown on (100)MgO and (100)YSZ, under identical conditions were highly c-axis oriented. Resistance vs. Temperature measurements of the films showed a Tc ( R= O) between 85 to 90K. Microbridges were patterned on these films and microwave induced Shapiro steps due to ac Josephson effect in the grain boundary weaklinks were clearly observed in their I–V