We have established a low-temperature process for the preparation of high Tc superconducting films by rf-magnetron sputtering. The films were deposited under sufficiently crystallizing and oxidizing conditions at (650°C), that is lower than the tetragonal-orthorhombic transition point. The as-grown Er-Ba-Cu-O film on a MgO substrate exhibited a sharp superconductive transition with zero resistance at 86K. The zero resistance temperature of the as-grown film on a SrTiO3 substrate was 80K. This process prevented the diffusion at the interface between films and the substrates, and thus reduced the porous structure in the films.
Thin films of Bi-Sr-Ca-Cu-O and Tl-Ba-Ca-Cu-O systems have been prepared by rf-magnetron sputtering and subsequent annealing. These thin films showed a highly oriented structure with c axis perpendicular to the substrates. The Bi-Sr-Ca-Cu-O thin films on MgO exhibited a superconducting transition with a zero resistance temperature (Tc=104K) and the Tl-Ba-Ca-Cu-O thin films on MgO also exhibited the transition at Tc=102K.
