Thin film preparation and single film device fabrication in the Tl-Ca-Ba-Cu-O HTS system

Superconducting polycrystalline thin films in the Tl-Ca-Bu-Cu-O system have been prepared by electron beam evaporation followed by appropriate sintering and annealing. Transition temperatures to 110 K and critical current densities to 600,000 A/sq cm have been attained in oxygen annealed films. However, with only 16 minutes of air sintering and no oxygen anneal, oriented films have been obtained with T sub c's to 107 K and J sub c's to 450,000 A/sq cm. Single film devices utilizing a parallel array of weak links and a coplanar control line have been fabricated from the films. Oscillators as well as AM and FM modulators operating between 3 and 6 GHz have been demonstrated using this device concept.