High Temperature Superconducting Oxide Films

We have used sputter deposition with single oxide targets and metal molecular beam epitaxy to prepare thin films of the high-T_c oxide Y-Ba-Cu-O superconductor. The processing parameters, the structural characteristics, and the transport properties of the films are reported. We also discuss the microstructures of superconducting Y₁Ba₂Cu₃O₇ thin films epitaxially grown on SrTiO₃ (100) substrate. The high density of twin boundaries found in thin-film samples seems to correlate well with the observed high critical current density.