Barrier technology for DyBa2Cu3O7-x junctions and related structures

Layered structures which include the high-temperature superconductor DyBa₂Cu₃O_7-x have been fabricated using molecular beam epitaxy with ozone as the activated oxygen source. A c-axis-oriented DyBa₂Cu₃O_7-x thin film with a T_c of 74 K has been grown on a layer of the rare earth sesquioxide Dy₂O₃ on a (100) oriented SrTiO₃ substance. Dy₂O₃ has also been incorporated as a barrier between two layers of DyBa₂ Cu₃O_7-x, where the T_c of the top layer is 89 K. X-ray diffraction reveals oriented growth of both the DyBa₂Cu₃O_7-x and the Dy₂O₃ layers. Cross-sectional transmission electron microscopy shows the detailed matching of the layers, demonstrating that the interfaces are abrupt, with {100} Dy₂O ₃ planes parallel to {001} DyBa₂Cu₃O _7-x planes. These results are an indication that high-quality, all-high-T_c superconductor tunneling junctions can be fabricated in this system