High-T_c (95 K) As-Grown Superconducting Bi-Sr-Ca-Cu-O Thin Films

Abstract

As-grown superconducting thin films of the Bi-Sr-Ca-Cu-O system were prepared on MgO(100) substrates by a three-target rf magnetron sputtering system with a regulated shuttering technique. Using this system, Bi-Sr-Ca-Cu-O superconducting high- T c -phase films (700 Å) with a thin Bi-Sr-Cu-O semiconductor-like-phase buffer layer (70 Å) were deposited on MgO (100) substrates under rigorous control of the film composition at 760°C. The superconducting transition temperature of the as-grown film was 115 K ( T c on ) and 95 K ( T c zero ). The surface of this film was very smooth and uniform.