YBa2Cu3O7-x films on flexible, partially stabilized zirconia substrates with fully stabilized zirconia buffer layers

Textured polycrystalline YBCO films with superconducting transition temperatures of ∼90 K have been prepared on flexible zirconia substrates, partially stabilized by 3 mol % yttria. X-ray data suggest undesirable (013) and [(110) (103)] texture in minor amounts within the predominantly c-axis oriented film. The transmission electron microscope data reveal clean, special crystallographic as well as silicon contaminated grain boundaries containing amorphous phases. By depositing a zirconia buffer layer, fully stabilized by 9 mol % yttria, we have demonstrated that the normal-state metallic and superconducting properties of the YBCO films can be considerably improved. These films exhibit critical-current densities of ∼0.9×104 A/cm2 at 77 K in zero field and 2×105 A/cm 2 at 4.2 K in zero field.