Preparation of Superconducting Bi-Sr-Ca-Cu-O Thin Films by dc Magnetron Sputtering

Abstract

Superconducting thin films of the Bi-Sr-Ca-Cu-O system have been prepared on MgO substrates by dc magnetron sputtering and subsequent heat treatment in order to examine the preparation conditions. The as-sputtered films deposited at substrate temperatures of about 750°C had a slightly crystalline structure and exhibited a superconducting resistive transition from 80 K to 30 K. The annealed films exhibited a superconducting resistive transition between 100 K and 80 K. Large resistivity drops at 110 K were observed when the films were deposited at relatively high substrate temperatures ranging from 650°C to 750°C and heat treated at approximately 885°C in air.