Superconducting and structural properties of sputtered thin films of YBa2Cu3O7−x

We have fabricated thin films of YBa2Cu3Ox by dc triode sputtering from two metallic targets. Post-annealing in pure O2 after sputtering resulted in superconducting films with a Tc onset as high as 89 K and a midpoint Tc of 75 K. We report preliminary results of films deposited on sapphire, MgO and sol-gel coatings of ZrO2 on sapphire, with and without buffer layers of Ag. The chemical and physical structures of these films were analyzed by using several x-ray diffraction techniques and Rutherford backscattering spectroscopy.