Preparation of Yb-Ba-Cu-O Superconducting Films Using an Arc Discharge Evaporation Method

We report a new process for preparing superconducting films of YbBa2Cu3O7-x using DC arc discharge evaporation on insulating substrates such as SrTiO3(100) and MgO(100). The films were deposited without intentional heating and subsequently annealed typically at 950°C for 2 hours in O2 atmosphere. Although the as-deposited films were amorphous and insulators, the annealed ones on MgO substrates showed superconductivity with Tcend(zero resistivity)=78 K. However, the films on other substrates (Y-stabilized ZrO2, SrTiO3, and Al2O3) did not show superconductivity down to 30 K. It was found from X-ray diffraction analysis that the films on MgO were predominantly oriented with the c-axis perpendicular to the substrate.