High-current superconducting Tl1Ba2Ca2Cu3O<i>y</i> thick films on polycrystalline Ag by spin coating

Abstract

Thick films of the high-temperature superconductor Tl1Ba2Ca2Cu3Oy with high current density Jc have been deposited on polycrystalline Ag substrates by a spin-coating method. The spin-coated precursor films were annealed in a two-zone Tl reaction furnace. Film thicknesses ranged from 10 to 30 μm, leading to good total current capabilities. The films have highly-textured c-orientation as evidenced by rocking curves with FWHM of 4° for the (006) peak. Scanning electron micrographs revealed a dense, plate-like layered structure and almost no reaction between the film and the Ag substrate. Values of Jc (77 K) up to 2.5×104 A/cm2 in zero field and more than 1000 A/cm2 in a 1 tesla field (H∥c axis).