PROPERTIES OF SUPERCONDUCTING Tl sub 2 Ba sub 2 Ca sub 2 Cu sub 3 O sub 10 FILMS BY SPUTTERING.

Rapid progresses have been made on thin films of high T sub c superconducting perovskites. Here, we focus on the results from one of the most studied oxide systems, 125K Tl-Ba-Ca- Cu-O. We have produced single-phase high T sub c superconducting Tl sub 2 Ba sub 2 Ca sub 2 Cu sub 3 O sub (10) films 0.2 to 1.0 microns thick on MgO(100) and SrTiO sub 3 (100) substrates by sputtering using a single oxide target. The Tl sub 2 Ba sub 2 Ca sub 2 Cu sub 3 O sub (10) films have a T sub c onset at 125K and a T sub c (R=0) at 116K. Transport critical current densities of these films on SrTiO sub 3 substrates are as high as 10 sup 5 A/cm sup 2 at 100K. These Tl-based films are not only strongly textured with the c-axis perpendicular to the film plane but also epitaxial to SrTiO sub 3 (100) substrates.