Preparation and properties of a capacitor structure formed by doubled-sided YBa2Cu3O7-x films on SrTiO3 substrate

The preparation of high-temperature superconducting YBa2Cu3O7-x thin films on both sides of the SrTiO3 substrate by DC magnetron sputtering is reported. The films on both sides of the substrate exhibited well-oriented crystalline structure with the c axis normal to the substrate surface, Tc=80-91 K and Rs less than 0.05 Omega at 77 K and 60 GHz. The properties of the resultant SrTiO3 capacitor with YBCO electrodes were examined at frequency of 1 GHz. The following parameters were obtained: relative dielectric permittivity of 4*103 at 77 K and dielectric loss tangents of 3*10-4 at 77 K. No hysteresis in the dependence of the capacitance on the DC bias voltage was observed.