Solid phase (RE ₂BaO ₄)-Liquid phase (BaCuO ₂) reaction: The way to highly oriented ErBa ₂Cu ₃O _y superconducting thick films on commercial silver substrates

Using a solid phase-liquid phase reaction we developed a new technology for preparing c-axis oriented thick ErBa ₂Cu ₃O _y (Er-123) films on commercial polycrystalline silver substrates without the need for a buffer layer. The films were processed in Ar-1% pO ₂ atmosphere. Using a double-step annealing, thick Er-123 films were grown, with the onset T _c of about 92 K. Formation of large flat grains with the preferential c-axis orientation was confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction. The magnetic self-field critical current density at 77 K was above 40 kA/cm ². This technology requires only a short processing time and thus is appropriate for utilization in long-length RE-123 silver-sheath wire production.