Abstract
High Tc superconducting thin films were prepared by rf magnetron sputtering. The composition of the prepared films strongly depended on the oxygen partial pressure of sputtering gas. The crystal structure of the films was determined by the substrate temperature during sputtering. The crystal growth was affected by the substrate crystal materials. Thin film of Ga-Ba-Cu-O was grown at 600°C by sputtering without suffering the postannealing. That offset temperature was 80°C with the onset resistivity of 1.6 × 10-4Ω⋅cm at 92K and the critical current density of 6 × 106 A/cm2 at 4.2K. The preparation of stoiciometric films using the proper sputtering conditions will realize the epitaxial single-crystal at the substrate temperature under 600°C and the superconductivity superiour to that of bulk ceramics.
