Preparation of new high-T_csuperconducting oxide Bi-Sr-Ca-Cu-O thin film by electron beam deposition technique

Thin films of Bi-Sr-Ca-Cu-O superconducting oxide were prepared by electron beam deposition of Bi, SrF₂CaF₂and Cu on (100) MgO substrates followed by annealing in oxygen gas flow. Onset transition temperature is 110 K, and resistance drops to less than 5% of the value in the temperature range T_c+4 K, although zero resistance is observed at 60 K. Between 110 K and 60 K, there exist at least 2 resistance drops, indicating multiphase superconductors with different T_cs. X-ray diffraction analysis reveals that the films are highly oriented so that the c-axis is normal to the substrate and has a length of 30.605°.